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281,478
Overhead associated with DBCC CHECKTABLE?
Have a logshipped VLDB and don't run DBCC CHECKDB on primary due to the long running periods of high CPU and tempdb usage. Have read about DBCC CHECKTABLE as a possibility for a more granular data integrity checking option. Does DBCC CHECKTABLE have overhead levels similar to DBCC CHECKDB ? Can it be run during busines...
The code behind CHECKTABLE is indeed likely the vast amount of time spent by CHECDB, as mentioned by @Mo64. I.e., the "sum of CHECKTABLE" should roughly be the same as a CHECKDB, one can imagine. However, by default CHECKTABLE uses a database snapshot. Not a "table snapshot", since there is no such concept. I.e., you c...
0
1
204
2020-12-13T23:47:29.107
data_quality
dba.stackexchange.com
1,034,551
Postfix not starting. How to resort to default settings?
I just changed this "Use TLS for SMTP connections" and I turned inet_protocols = all to inet_protocols = ipv4 and then back to what it was. Reloaded the configuration a couple of times. Now, it won't start. Please help. I am a layman just trying to set up my own email server. Ubuntu/Webmin/Virtualmin
Always have a copy of your original configuration files before starting to edit. If you messed up the configuration, rollback the changes you made on config file and reload. That should do the trick, otherwise remove the files and reinstall Postfix.
0
1
776
2020-09-19T15:03:12.777
infrastructure
serverfault.com
533,596
Amazon ELB HTTPS Not working
I'm trying to get HTTPS working with AWS ELB. I've been trying for about an hour, but no matter what i try, i just get connection timed out when connecting via HTTPS. HTTP works fine, but not HTTPS. Can anyone provide some assistance?
Don't forget to allow port 443 in the security group . That's what was causing it to timeout for me. If you're using Elastic Beanstalk (EBS), you should tweak SSL settings directly in EBS config and it'll update the ELB and security groups as required. If you update it directly in EC2/ELB interface, even though you can...
9
11
6,028
2013-08-25T12:43:48.793
infrastructure
serverfault.com
176,737
Filter extended event xml_deadlock_report by database
I have added an extended event log that logs [CODE] events and [CODE] events. I can exclude certain databases from the blocked_process_report by adding [CODE] . But how do I exclude a database's [CODE] events? The property " [CODE] " appears to be set to " [CODE] " for a deadlock event, no matter where the deadlock occ...
I am using [CODE] SSMS: [CODE] I can create a filter for deadlock without any error. [CODE] Here is the picture where I am adding filter (if I am using GUI).
0
1
1,349
2017-06-20T09:05:46.910
database_errors
dba.stackexchange.com
885,534
Handling collision with mail addresses in local (send-only) postfix and external mail provider
I have a domain [CODE] pointing to my server and have MX entries redirecting to an external (!) mail provider where I can send and receive mails via [CODE] . Since I am running some applications on my server that should send mail notifications I have installed postfix with the following changes to [CODE] : [CODE] And t...
I found the solution that helped me achieve what I want and it's described here . Basically I had to change the [CODE] in [CODE] to be empty to prevent local delivery. On top of that I changed my maps to exclude the second [CODE] line and replaced the [CODE] with the postfix username.
0
0
17
2017-11-28T14:42:43.677
infrastructure
serverfault.com
737,834
can't rdp to work desktop over vpn by name
I have a couple of users that are having the same issue. They can VPN in to our local site but once the VPN is established they can only RDP to there desktop using the IP address. I have had a user test this and when they ping their work desktop from home, after the VPN connection is established, by IP address she gets...
I guess your VPN clients are not using your Internal Office DNS servers when connected, and that's why can not resolve the internal hostnames correctly. You need to make sure that you configure your VPN server so that the clients, when connected also recieve the internal namservers (those you use in Office lan). Then t...
-1
0
3,741
2015-11-20T15:41:41.847
infrastructure
serverfault.com
87,006
Query from 1st domain and insert in 2nd domain
I have data in one of my websites. I want to print these data in other site. These two are in same server. At present, I have to export MySQL data and import into other then do this code to insert in 2nd domain. I want to link directly so that I can make data request from 1st website and show in 2nd website. I know for...
Your [CODE] statement seems incorrect. [CODE] This grants the [CODE] privilege on all tables ( [CODE] ) in a database called "database-name.tableA". The correct statement would be this: [CODE] Since "database-name.tableA" isn't a valid database, userA can't possibly have permission to access it. When a user tries to gr...
1
1
288
2014-12-25T16:20:13.307
database_errors
dba.stackexchange.com
1,110,353
libvirt/qemu VM freezes when migrating between specific hosts
I have several servers (different ages) running on Ubuntu 22.04 with QEMU and libvirt. When migrating VMs between some of these servers, the VM immediately freezes on the target system. Tested guests were HVM machines running current Ubuntu or CentOS/Rocky Linux. Previously the servers ran on Ubuntu 18.04 and were rein...
I experienced the same problem after migrating my KVM hosts to Ubuntu 22.04. Solution The Solution in my case was an upgrade to the hwe-22.04 kernel (at the time of writing: 5.19.0-32-generic ). Since Ubuntu Server installations don't get the hwe kernel automatically, I used the following command to install it manually...
2
1
920
2022-09-09T17:42:58.183
infrastructure
serverfault.com
338,106
PC inventory system that does not rely on WMI
I'm looking for a software that can make an inventory of the PCs on your network for an SMB environment. I know ther are plenty (Spiceworks, LanSweeper, etc). But they all rely on WMI to function. The problem is I have so many problems with getting WMI to work on all workstations that I'm looking for a more reliable al...
Check out OCS Inventory http://www.ocsinventory-ng.org/en/
0
3
528
2011-12-06T12:11:13.497
infrastructure
serverfault.com
297,700
RDS PostgreSQL -> aws_lambda.invoke error: 'Unable to connect to endpoint'
[CODE] IAM role with correct policy attached to RDS instance confirmed with Access Advisor. Interface endpoint for Lambda set up in VPC/subnets. Lamba test runs successfully. Can't find anything on the interwebs (even this forum). Any help appreciated.
We just had the same issue and managed to get it fixed after digging for few hours. What we have done is basically include an Outbound rules (443) in our database Security Group. Invocation just went through after that. I guess it is because the invocation is FROM postgreSQL TO lambda. Hope this helps the next reader.
0
3
1,530
2021-08-06T18:16:16.013
database_errors
dba.stackexchange.com
776,320
Does changing the openvpn server config affect already issued certificates?
We've got an OpenVPN server running that is in use, with a number of static clients defined and certificates issued. However, over time it's become apparent the the IP pool currently available isn't going to be sufficient. We can change the config on the server to something like: [CODE] To open up the entire 10.8. . cl...
To your first question about certificates: Changing the subnet will not affect existing certificates. To your second question about the static clients: It depends on your setup. According openvpn manpage: [CODE] If you change your subnet, the correct routes will be pushed to your clients automatically. If you use [CODE...
2
0
2,757
2016-05-12T09:49:45.003
infrastructure
serverfault.com
323,552
Why is my non clustered index causing this deadlock?
I have an application that runs the following query in multiple parallel threads: [CODE] Order_ID is NOT the primary key on this table, but the @orderID is different for each thread, this update used to run fine until a non-clustered index was introduced: [CODE] After this index was introduced, the following deadlock s...
How could my index be causing this deadlock and how should it be fixed without complete removal of the index? Because the plan must scan the entire index to find the rows with that @orderid. So each session has found an updated a row, but the other session needs to read that row to see if it has the target @orderid.
1
4
83
2023-02-15T14:40:56.183
database_errors
dba.stackexchange.com
89,687
PostgreSQL: Use column with hash based on other columns as unique index?
My previous problem is still not fixed: We cannot set a unique index because NULL values are allowed... we use this table in our database: [CODE] And we use a unique index which doesn't work: [CODE] But the unique index doesn't work because price_old, price and price_alt can be NULL.... It's possible that only price is...
PostgreSQL 15 and higher For PostgreSQL 15 and higher, this is solved by having the [CODE] support for unique constraints: For the purpose of a unique constraint, null values are not considered equal, unless NULLS NOT DISTINCT is specified. https://www.postgresql.org/docs/15/sql-createtable.html [CODE] PostgreSQL You c...
1
2
9,749
2015-01-20T10:27:48.093
database_errors
dba.stackexchange.com
454,772
Calendar sharing between unrelated Domains
I have a 'request' from one of the 'big guys' that has me scratching my head a bit. He is one of our Executives that also is a board member of several other organistations, so he floats around between 4 different unrelated companies, each with their own domains, Exchange setup etc. He has domain accounts in each organi...
You can share free/busy data across Exchange organizations using Active Directory Federation Services. This will require ADFS endpoints at all organizations, but it will do what you want. Of course, whether or not you can convince three other organizations to buy into this is probably not going to happen :)
3
3
314
2012-12-04T00:46:56.437
infrastructure
serverfault.com
209,013
What are some real world applications that generate large numbers of records in a database every day and what are those metrics?
I'm trying to get some perspective in today's day and age what is considered a large amount of data or large number of records generated in a day and what real world applications are doing that. I would guess large banks have to be generating many records every day in their systems, and I wonder just how many this actu...
Trading. I was part of a DWH team for a larger trading outfit and we generated 110 million update rows per day on existing contracts. Requirement to keep them for years. Now I dabble in the field, and my validation systems have peaks of around 500 million rows per day, but we only keep those for a week or so. how do th...
-3
2
114
2018-06-07T14:36:15.273
warehouse_errors
dba.stackexchange.com
394,663
update from debian lenny to squeeze
I'm trying to update from debian lenny to squeeze on my 64bit root server and did the following so far: modifying sources.list apt-get update apt-get upgrade apt-get install linux-image-2.6-amd64 The last step leads to the following error-output: [CODE] UPDATE here's my sources.list [CODE] UPDATE 2 I could also run [CO...
It seems you started off with the recommended procedure for upgrading which is great. I recommend trying to stick to that instead of prematurely doing a dist-upgrade. This procedure is worked out by testing on thousands of systems and is what we think is your best chance of a smooth upgrade. In this case when you are d...
0
3
3,954
2012-06-01T10:29:16.690
database_errors
serverfault.com
813,313
pfSense BGP and NAP
We have an AS number for a C class (/24) and 2 providers. Currently I have a Fortigate and a pfSense in the network. Fortigate is doing the BGP, and pfSense is doing the NAT, DMZ, VPN, VLAN. We are using 1 IP to route all internal traffic, 1:1 NAT for DMZ servers, I want to have everything in pfSense. I haven't seen an...
Possible, yes. Good idea, eh, probably not. OpenBGPD has stability issues at times, and there are inherent complications in stateful filtering and asymmetric routing. pf also performs poorly under DDoS, likely making it difficult to stay online even with a small scale attack. The network edge where you're doing BGP is ...
0
0
1,255
2016-11-04T22:33:00.067
infrastructure
serverfault.com
667,462
Multipath configuration is ignoring drives after /dev/sdaa, /dev/sdab, etc
I have a bare metal server running on Softlayer. It has many Consistent Performance iSCSI storage devices attached in a multipath configuration . One of the devices, represented by /dev/sdaa1 and /dev/sdab1, is not showing up as a multipath device under /dev/mapper. How can I make it show up?
The problem was that the multipath blacklist in [CODE] had been amended to exclude /dev/sda1: [CODE] The regex above catches /dev/sda1 as intended, but it also catches /dev/sdaa1 and /dev/sda_foobar. To fix, amend the blacklist to include the end of the device name: [CODE] After amending the blacklist, reload the confi...
0
0
1,140
2015-02-13T17:41:22.230
infrastructure
serverfault.com
65,569
Improve MySQL Query Performance - Too many records
I am using MySQL RDMS for a contact management system. Now a days my database grew in size and contains more than 1 million records. Checking duplicate phone numbers became a big issue during administration process. My server load drastically increases when I do search for phone numbers in the entire database. Since I ...
I'd recommend to not have three columns [CODE] , [CODE] and [CODE] , but have a related table for phones , and have your data fully normalized (or, further normalized): [CODE] Your check now is only: [CODE] On average, this will be 3x faster ... and you can have 0, 1, 2, 3 or any number of phones for a given [CODE] , a...
3
1
3,467
2014-05-21T12:58:46.943
data_quality
dba.stackexchange.com
205,931
Creating a structure to allow for optional teams of people rather than just individual people
I currently have a database set up that has tables as follows: [CODE] Currently each developer can have one or more projects in the project table. I am now wanting to provide an option for having team management and a team of developers for companies that want to manage entire teams. However, still want the original me...
Am I on the correct track of thinking here? IMHO you are not. You are putting the carriage in front of the horse. To get back on the right track, start at the beginning, with your data universe. Let's list what entities you have in your game, and separate that from the business rules. First question is: "what is it in ...
3
3
377
2018-05-05T16:12:16.030
pipeline_ops
dba.stackexchange.com
128,575
Improve performance of query with multiple group by column and count function in select
Brief Background of issue We have a aggregate table to store rows and this table have currently 3 Million rows and we need to retrieve data from this table. Query for this data is taking too much time. Data in this table increasing at 1 million rows/month rate. We are using [CODE] with version [CODE] Table structure is...
[CODE] int(11) NOT NULL COMMENT '1. chatter, 2. marketing', -- Change to [CODE] . This will save 3 bytes per row. Ditto for several other fields. And for those fields that are also in indexes, especially the PK, that "3" gets multiplied. [CODE] -- If you are not expecting more than 4 billion, save 4 bytes each by switc...
2
1
3,355
2016-02-08T10:35:45.940
warehouse_errors
dba.stackexchange.com
7,536
If you favor "T *var", do you ever write "T*"?
Possible Duplicate: int* i; or int *i; or int * i; Thinking about where we place our asterisks ; how do those that prefer to keep the "pointerness" away from the type and with the identifier ( int *i ) write code when the identifier is missing? [CODE] The former seems much more common, no matter what your preference wh...
The goal should be to make the code readable and clear. The style [CODE] may seem fine, but when it becomes [CODE] it implies something different than what it really is. Contrast with [CODE] and [CODE] where each reads exactly like the way it works. The difference between [CODE] and [CODE] for readability is negligible...
12
16
1,834
2010-09-27T10:02:49.717
data_quality
softwareengineering.stackexchange.com
647,611
How disabled log apache for image file missing?
How can we specify extensions file to filter it in log error of apache? My error.log fills with : [Thu Nov 27 22:42:42 2014] [error] [client 42.42.42.42] File does not exist: /var/www/site/images/foo.PNG In my case, I want avoid .png, .jpg, .gif to error log when they are missing. How can I do that?
Well the best idea would of course be to fix the site contents so there are no broken image links ;) With regards to the [CODE] : It is not possible to customize the error log by adding or removing information. So you can't exclude specific error messages. It is possible to increase or reduce the verbosity of the Error...
0
3
774
2014-11-27T19:45:40.970
infrastructure
serverfault.com
1,056,379
Server settings to improved Wordpress backend speed
You know how it is, caching plugins only make the front-end move faster but when you're logged in and browsing the wp-admin section, the Wordpress site grinds to a halt. I'm trying to increase some backend speed of my Wordpress site and would like to know what are the best PHP and server settings to get the speed impro...
Memory limit and time limit do not affect speed, neithed does PHP Max Input Vars. Best option for speeding up backend is to use a proper caching plugin which caches database queries, provides a memory-based store for Object caching and transients. This will reduce the need to make calls to database, which will speed up...
0
1
53
2021-03-09T02:01:59.400
api_errors
serverfault.com
691,215
OpenStack cartridge-add gives github could not read username error
I am trying to add a paper trail cartridge to an existing Wildfly 8.2.0 gear with the following command: [CODE] I keep running into this error: [CODE] I cant seem to figure out how to remote add this git repo to my gear. Any help is appreciated. Thanks.
I don't understand where you are getting the command you are trying to run. If you want to use the [CODE] service, then using the documentation found here I believe the command would be: [CODE] If you just want to install the cartridge directly, then just use the command they give you on the project's GitHub page : [CO...
0
0
97
2015-05-11T18:19:45.610
infrastructure
serverfault.com
137,551
--prefix to /usr/local or /opt?
For building apps from source like git or rails I've seen recommendations to install in both /opt or /usr/local. From what I've read so for, the designated use for both is about the same and it amounts to merely a style issue. Is there any practical difference? Best practices?
The FHS says: A package to be installed in /opt must locate its static files in a separate /opt/ or /opt/ directory tree, where is a name that describes the software package and is the provider's LANANA registered name. while /usr/local hold the usual /bin/, /lib, /etc, ... hierarchy
5
3
1,066
2010-04-30T21:35:58.250
infrastructure
serverfault.com
69,944
Are #tables and #procedures 'not best practice' or 'bad practice'?
I am working on a project and part of it is an interface tool that executes SQL code stored in a xml file to import/export files. In the file, temp procedures and temp tables are used quite heavily (list of imported/exported records, logs, support tables, stored procedures for easier reading etc). It has been decided b...
I doubt that the example you provide is a valid use case for temporary procedures (I don't see any benefit here to using #temp procedures over permanent procedures), but for #temp tables, which have a much wider set of use cases, the only way to fight these arguments with policy-setters is to run the code - using a ful...
0
2
470
2014-07-08T13:23:30.880
pipeline_ops
dba.stackexchange.com
607,273
Trouble configuring standard VLANs on BNT G8264 and ESXi 5.5
I have a BNT (now an IBM) RackSwitch G8264 and am having problems trying to get standard VLANs configured and working with my two ESXi 5.5 hosts. I've followed the documentation (which can be found here ) for the version of switch software I am running, and I believe I have configured the VLANs correctly. However, when...
The vSwitch should have no special configuration. Your port groups should contain all of the actual VLAN tags. On the switch side, is VLAN 1 actually defined anywhere? See my example from: vSwitch configuration with 12 uplinks There's nothing untagged at the vSwitch level because it makes more sense to associate port g...
1
2
3,346
2014-06-23T13:06:20.210
infrastructure
serverfault.com
1,045,128
AWS backup is not in the list of command line interface commands
When I'm trying to use [CODE] on my AWS server through command-line interface, but it's not in the list of available commands. How do I add this in? Currently when I run [CODE] I get the following: [CODE] etc. there's no [CODE] in there. How do I launch [CODE] commands then?
Upgrade your aws-cli . More likely than not you’ve got an old version that doesn’t yet have backup support. What’s your [CODE] output?
0
2
107
2020-12-05T18:08:40.570
database_errors
serverfault.com
1,033,228
How does everyone manage a multi server environment and their credentials with ansible?
I'm trying to figure out the cleanest and/or most secure way to manage a multi server (linux) environment in AWX/Tower/Ansible. I've seen a few posts around this topic, but there doesn't seem to be a clear answer on which approach is the most secure. Let's say I want to use a single template/playbook against 20 differe...
I have implemented this by having a private key for the [CODE] user to log in and specifying system specific [CODE] in [CODE] . [CODE] user belongs to the [CODE] group naturally. This way there is SSH key security on the user account itself and unique password for each host, generated by Ansible when first provisioning...
0
2
897
2020-09-09T14:07:09.170
pipeline_ops
serverfault.com
223,148
Two months in my new job, still having trouble learning a new codebase. How can I improve?
I'm a self-taught programmer. Up until now I haven't had too much problems building things I have wanted to. Historically, given an issue, especially one I have caused I haven't had much of a problem figuring it out. This all changed about two months ago, when I was offered my first position at a company whom I became ...
I have had good success to learn new code bases with the following approach. Strive to understand: Purpose: understand what the system or framework does, conceptually speaking Architecture: create a view on the overall architecture of the system or framework Components: learn how major parts (components) work together ...
5
13
6,317
2014-01-05T01:23:50.047
data_quality
softwareengineering.stackexchange.com
163,861
Ubuntu guest (virtual box) doesn't show on the router
I installed Ubuntu (as a virtual machine using virtual box) with the openssh server option and apache. When I do [CODE] I see apache is running. But: I can't connect to the server from the browser (for example http://192.168.1.8 ) I don't see the new server on my router's list of connected devices I can't putty to that...
Is your VM configured to be in bridged mode? If not, change it to bridged mode so that your VM will appear as just another machine on your network.
0
1
724
2010-07-25T09:20:01.517
infrastructure
serverfault.com
275,794
How to determine whether two trees (not necessarily binary) are isomorphic
Two ordered trees T' and T'' are said to be isomorphic if one of the following holds: ◦ both T' and T'' consist of a single node ◦ both T' and T'' have the same number k of subtrees, and the ith subtree of T' is isomorphic to the ith subtree of T'', for i = 1, 2, ..., k. I've made an attempt to come up with the followi...
What Giorgio said. Just change the function so that it iterates over a list of children instead of checking only a left and a right child (assuming that's how the non-binary tree you're interested in is implemented).
0
1
4,196
2015-03-10T05:52:08.773
api_errors
softwareengineering.stackexchange.com
1,070,069
ARP Proxy second IP of VPS to route it over Wireguard
I have set up an ARP Proxy on my VPS. With this Setup, I can route incoming traffic on the second IP of my VPS over WireGuard. This should allow my Raspberry Pi at home to use the second Public IP. I got this kind of working. Incoming Pings are forwarded over the WireGuard Tunnel to the Pi. But the Pi then tries to ans...
I think you should be able to do this with policy routing. Set up the default route for a new routing table ( [CODE] for example) to use your WireGuard interface ( [CODE] ): [CODE] And then add a policy rule to use that new table for all packets whose source is your Second VPS IP (say it's [CODE] for example): [CODE] P...
0
0
1,254
2021-07-19T23:45:06.820
infrastructure
serverfault.com
818,237
Is SNMP v3 supported in Windows Server 2016?
Hello serverfualt members, I have researched this very question and have made the following discoveries: Windows 2003 Supports: • SNMPv2x Windows 2008 Supports: • SNMPv1 and SNMPv2c Windows 2012 does not Support SNMP: • SNMP is deprecated. Instead, use the Common Information Model (CIM), which is supported by the WS-Ma...
Windows Server 2016 does not support SNMPv3 . Microsoft officially states that SNMP is deprecated in Windows Server 2012 and up, so I doubt you'll be seeing anything from Microsoft in the future either. They are all into WinRM and Powershell remoting now. We've had a similar issue a while ago. The way to achieve Window...
10
7
38,845
2016-12-01T20:55:35.713
infrastructure
serverfault.com
821,121
why after swap increasing and swapoff and swapon , swap total return to the previous value
in my Linux redhat machine ( version 5.x ) I perform the following steps in order to increase the swap from 6G to 8G [CODE] after steps swap increased successfully to 8G after two days I perform swapoff -a and swapon -a but I noticed that total swap is only 6G as before my steps ! Please advice what was wrong in my ste...
You should check "/etc/fstab" file first whether there is swap partition entry there or not. "swapon -a" command will check the swap partition entry from "/etc/fstab" and assign swap memory from that partition. You can add line below in fstab. /dev/mapper/rootvg-swap1 none swap sw 0 0 Than try "swapon -a" command.
1
1
1,022
2016-12-16T12:01:56.453
infrastructure
serverfault.com
741,409
How to configure auto-scaling with Bamboo Agents?
We are able to launch new Bamboo agents and register them with the Bamboo server by using AWS auto scaling groups and using the user data, but scaling down is an issue. A Bamboo agent is like a Jenkins slave. How can we automatically scale the bamboo agents cluster down e.g. from 12 to 8 nodes without killing current b...
Bamboo has "Elastic bamboo" which takes care of bringing up new agents and taking them now as required. You can configure "elastic bamboo" from the bamboo server, in the admin section.
2
1
762
2015-12-07T22:12:30.660
pipeline_ops
serverfault.com
664,301
Installation of Netkit-Ng on CentOS
I want to install Netkit-ng on CentOS, I executed those commands : [CODE] This is what I get by running the last one : [CODE] How can I fix that? thank you
That error message comes from the file [CODE] , in which the following check is performed: [CODE] Judging from that, it's possible that the [CODE] environment variable is not set, or the file [CODE] is not execute (on my system it was). Also note that Netkit-NG seems to be built for Debian, so it might be impossible or...
0
0
1,299
2015-02-02T11:28:20.907
infrastructure
serverfault.com
418,585
is there difference between releasing two semaphores in the same or reverse order as they are acquired?
Generally, if two semaphores are acquired one after the other, is there difference between releasing them in the same order or the reverse order as they are acquired? In the following solution to the third readers-writers problem from http://en.wikipedia.org/wiki/Readers%E2%80%93writers_problem#Third_readers%E2%80%93wr...
The only difference is that the service queue becomes available one nanosecond before the readcount queue. So someone getting on the servicequeue can request access to the readcount queue one nanosecond before it becomes available, but there are situations where you have to wait a lot longer. It would be preferable to ...
-1
1
147
2020-11-02T11:16:46.057
api_errors
softwareengineering.stackexchange.com
81,522
How to obtain a count of the classes of a categorical var within a certain time interval for a time-stamped data?
I have a dataframe with several categorical variables. But for simplicity let's assume there is only 1 categorical variables with 3 classes. I want to obtain the counts of these classes within a certain time-intervals, say 15mins. To make it easier to understand what I am looking for, here is a toy example and the outp...
[CODE] Output
0
1
375
2020-09-10T19:55:30.227
data_quality
datascience.stackexchange.com
556,047
Outbound HTTP traffic being blocked by APF - outbound filter is off
I'm using CentOS 6.4 inside an OpenVZ container. I'm trying to configure APF 9.7-2 to allow inbound SSH and HTTP traffic (only) and outbound HTTP and HTTPS traffic (don't care much if other outbound works). My conf.apf file is set to the defaults, with the following exceptions: [CODE] (Note that I have not enabled outg...
I've found the problem. The configuration for the container on the hardware node needs to have the correct iptables modules enabled. The default for containers on my server was: [CODE] I've overridden this in my container's configuration (/etc/vz/conf/CONTAINERNUMBER.conf on the hardware) [CODE] I'm not sure exactly wh...
1
0
639
2013-11-19T17:33:35.027
pipeline_ops
serverfault.com
100,537
Logistic Regression to model a rare event
I have a data set which has data on consumers and a flag for whether they have expressed interest in a product or not. I am looking to build a model using R which will be able to predict whether or not a consumer will be interested in the product, before they are shown the product. I will then be filtering based on thi...
Using [CODE] is not the right approach to model a binary outcome. You would use a Logit in this case (see some example here and see why not [CODE] here ). However, there are (at least) two more issues: You have a highly unbalanced target You may have "noisy" features Regrading 1: You should check if some oversampling o...
2
1
316
2021-08-26T13:19:18.323
data_quality
datascience.stackexchange.com
306,996
pg_restore "exceeds btree version 4 maximum 2704 for index" with no data exceeding that
Currently trying to migrate a Azure Postgres instance from pg11 to pg13, using pg_dump and pg_restore. However there's a problematic table that is complaining about a large index b-tree size, I suspect this is because of the postgres12 B-Tree byte size decrease, however when looking at the data I cannot find any data t...
Rather than believing that PostgreSQL lied to you, I'd assume that you made a mistake and there really are index keys that exceed the limit. When you measure the size of the rows, don't forget that PostgreSQL TOASTs large values either by compressing them or storing them out of line.
0
0
1,039
2022-02-04T05:28:27.930
database_errors
dba.stackexchange.com
1,149,109
How to serve static files for Docker Nextcloud-fpm behing nginx reverse proxy?
I have a similar problem to NextCloud FPM Docker Image behind an NGinX Docker Container as Proxy Reverse I have multiple web apps running in Docker containers behing a Nginx reverse-proxy. I'm trying to install Nextcloud 25 with the standard image (actually, I want to upgrade from owncloud to nextcloud but I want to ha...
The [CODE] was simply not correct. It was set as [CODE] where it should have been [CODE] Also the line [CODE] must not be commented. I'm just an idiot...
0
0
185
2023-12-04T18:07:51.973
pipeline_ops
serverfault.com
809,008
pgsql is not loading (centOS 6.8)
*First of all don't answer "php.ini >> uncomment extension=pgsql.so and restart httpd". did that millions of times, did not solve my problem. *Tried hundreds of methods described in different sites including stackoverflow, but unfortunately did not work for me (I am leaning Linux >> noob) INFO: httpd 2.2.15, php 5.6.26...
I updated PostgreSQL (as @RemiCollet suggested) and everything is working properly. [CODE]
0
1
2,751
2016-10-14T09:02:48.327
database_errors
serverfault.com
199,491
Can you rollback a query in state 'committing alter table to storage engine'
We've got an InnoDB table with 70 million rows, and we have been trying to run an alter table statement to modify and add a couple of columns. The query seems to have altered the table, and is now in the state of 'committing alter table to storage engine'. [CODE] This has been running overnight, and is at 19 hours at t...
I am sorry to have to inform you, but [CODE] cannot be rolled back. In fact, [CODE] triggers an implicit commit. According to Page 418 Paragraph 3 of the Book the following commands can and will trigger an implicit commit [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] [CODE] I have mention...
3
3
4,999
2018-03-06T14:08:33.477
database_errors
dba.stackexchange.com
84,607
Cannot ALTER TABLE
I have a particular table that I cannot add a key for: [CODE] Googling the issue it seems that this problem is often either a configuration issue or a disk space issue . In fact, this database is running on an Amazon RDS instance, which means that it is basically a managed server dedicated to MySQL with a very standard...
Try to repair the table: [CODE]
3
5
4,488
2014-12-08T15:52:12.170
database_errors
dba.stackexchange.com
270,719
MariaDB: Why is this still using temporary and filesort - is it because I'm using a self-join? How to fix?
[CODE] gives: [CODE] If I remove the [CODE] I get "Using index". What's the problem here? Is it something to do with joining a table onto itself? (The indexes present on the table are the two shown in the explain output, containing the columns that the names suggest.) DDL: [CODE]
Try to convert your query to [CODE] Update It seems that MariaDB uses implicit STRAIGHT_JOIN... or plan builder cannot optimize the query correctly. For query optimize it's enough to swap table copies. See fiddle for details.
0
0
328
2020-07-10T07:48:34.117
database_errors
dba.stackexchange.com
383,312
ISPConfig configuration alongside Apache Tomcat configuration
I was stumbled upon a problem, I followed up the tutorial from howtoforge to set up a web server (The perfect server running Ubuntu Server 11.10) to be able to host some Java Web Applications. So I installed all the necessary applications from this tutorial, but at the end I can't access ISPConfig from the browser of a...
First check these are running on [CODE] by pasting the output of [CODE] like so; [CODE] Then check that these should be accessible from other hosts on the network, by showing the firewall rules like so; [CODE]
0
1
2,209
2012-04-26T08:25:45.577
infrastructure
serverfault.com
759,919
Correct OpenWRT configuration for iptables PREROUTING rule
I've recently switch my router firmware from Tomato to OpenWRT. I had the iptable commands below which would intercept http requests to an internal ip (192.168.1.254) on port 80 and redirect to a different internal ip (192.168.1.133) on port 8082. This configuration is not working working on OpenWRT. I've entered it in...
After a few more hours of trying, I was able to get this working with the help of this article; https://www.debuntu.org/how-to-redirecting-network-traffic-to-a-new-ip-using-iptables/ My [CODE] command was not correct. Switching to the following command worked: [CODE]
1
1
6,124
2016-02-26T02:17:36.947
infrastructure
serverfault.com
827,206
If I restart xinetd service , does it impact the currently active FTP connections?
In my Linux system FTP server is running from xinetd . I want to make a configuration change inside the /etc/xinetd.d/ directory for the FTP server launch , with respect to the arguments passed to the FTP server . So for this change do I have to restart the xinetd service ? Also if I restart the xinetd service ,does it...
Make the changes you want to your configuration file and then do a graceful restart. This will force the process to reread it's configuration, while still serving active and established connections. After the reload, all new sessions will be served with the updated configuration. To do a graceful restart type: [CODE] (...
1
1
6,214
2017-01-19T06:30:03.730
infrastructure
serverfault.com
253,140
how do I disable autonegotation and force specific ethernet settings?
I have a Dell r710 (running Debian GNU/Linux 6.0) which is currently in a datacenter hundreds of miles away, and the ethernet card is stuck at 10baseT half duplex. 10baseT is OK, but I want it to be full duplex. The card in question is a broadcom BCM5709: [CODE] using the bnx2 driver/firmware: [CODE] And running the st...
It is better to have auto-negotiation enabled on both ends. This is the current recommendation of the networking vendors (including Cisco). See: http://www.cisco.com/en/US/tech/tk389/tk214/technologies_tech_note09186a0080094781.shtml For your problem, you have to find out how it is configured at the remote end. If it i...
3
3
44,193
2011-03-29T12:37:04.873
infrastructure
serverfault.com
297,847
Deciding number of Tomcat instances - share where possible, or embrace multiples?
We've only recently started using Tomcat (6.x) as our Java servlet container for various production web applications. We're not using particularly advanced functionality, and generally Tomcat config for each app is extremely simple. It seems to me that installing multiple Tomcat instances (which I understand is extra e...
If it can handle it performance-wise, I'd say use one instance - memory will probably be the main concern. The trade-off is extra management time and effort, pointing clients or proxies to extra listening ports, etc., against the potential performance issues with everything running on one jvm - eating the same memory h...
1
0
90
2011-08-05T00:24:23.470
pipeline_ops
serverfault.com
71,799
Have you ever dealt with writing a spec late in the development lifecycle?
We have an existing code base which has been developed to meet the needs of most of our clients, which has accumulated features and bug fixes as they were needed and as projects developed universally useful features. Right now, we're running into the problem that there's no real documentation for its capabilities outsi...
Doing it right now, actually. Test-Driven Reverse Engineering. Write some kind of overview as best you can. Create minimal unit test cases for each component. Minimal. Enough to show that the component does one thing correctly. If you already have unit test cases, use the existing cases as the basis for documenting wha...
4
7
135
2011-04-27T15:29:36.547
api_errors
softwareengineering.stackexchange.com
986,772
SSD or HDD for server
Issue I have read many discussions about storage, and whether SSDs or classic HDDs are better. I am quite confused. HDDs are still quite preferred, but why? Which is better for active storage? For example for databases, where the disk is active all the time? About SSD. Pros. They are quiet. Not mechanical. Fastest. Con...
One aspect of my job is designing and building large-scale storage systems (often known as "SANs", or "Storage Area Networks"). Typically, we use a tiered approach with SSD's and HDD's combined. That said, each one has specific benefits. SSD's almost always have a higher Cost-per-Byte. I can get 10k SAS 4kn HDD's with ...
74
97
50,917
2019-10-04T11:47:49.537
infrastructure
serverfault.com
484,992
GoDaddy VPS running Magento went down twice past couple of weeks
Would this PHP error possibly cause the server to go down? [Tue Mar 05 02:48:28 2013] [error] [client 50.57.68.9] PHP Fatal error: Uncaught exception 'Exception' with message 'File 'httpdocs/media/catalog/product/cache/1/' does not exists.' in httpdocs/lib/Varien/File/Transfer/Adapter/Http.php:96\nStack trace:\n#0 http...
Absent any other relevant information: No. An uncaught exception in PHP should not cause your web server to "go down". It will however make your PHP application bail out when it encounters the exception, which could have a variety of symptoms (blank page, page of error messages, etc.) that may be reported to you as "TH...
-3
1
266
2013-03-05T20:16:47.850
infrastructure
serverfault.com
563,285
nginx with php-fpm downloading php files rather than executing them on mac os x (local environment)
I'm having trouble getting PHP files to execute on my local development machine. I seem to have successfully installed nginx and php-fpm also seems to be correctly installed, and running but can't quite work out why PHP files are being downloaded rather than being executed. After many, many hours of frustration , I tho...
Instead of specifying the PHP section in the nginx.conf file, can you specify a server location in the default file (within sites-available directory) and either reload or restart nginx: [CODE] Also, make sure that your nginx.conf file has the following directive: [CODE]
6
4
16,967
2013-12-24T01:57:18.313
data_quality
serverfault.com
574,147
How to set up reverse DNS on Ubuntu 12.04 VPS
As far as I can remember when setting up my VPS and mail server on it, I had configured the mail server correctly. However, a few of my clients get SMTP errors, host mx1.zonnet.nl[62.58.50.9] said: 553 We do not accept mail from IP addresses without reverse DNS. See http://wikipedia.org/wiki/reverse_dns (in reply to RC...
You cannot set the reverse DNS yourself -- you have to ask your VPS provider to do that. With an IP of [CODE] the reverse DNS is basically a lookup of [CODE] , as described in the Wikipedia article. With a local BIND you might get a reverse DNS configuration on your own server, but nobody else would ask your server and...
3
8
9,785
2014-02-08T12:39:06.223
infrastructure
serverfault.com
333,302
CURDATE() is not valid at this position expecting an identifier
MYSQL [CODE] I want to set a default value in the hiring date to be the current date if no date is written in the column but nothing works [CODE] and [CODE]
https://dev.mysql.com/doc/refman/8.0/en/create-table.html Probably just missing parentheses around the expression: [CODE]
-1
2
79
2023-11-20T18:46:15.503
database_errors
dba.stackexchange.com
762,116
Disabling SSLv2 on Dovecot v1
I'm still using Dovecot v1 (1.1.20) on an osx server. I'm trying to disable SSLv2. Seem like the default config already disabled it: [CODE] But when I test my web server with ssllabs, it complaints my mail server (pop, imap) is vulnerable because of the use of SSLv2 (same key). I also tried: [CODE] With no more success...
SSLv2 is a protocol , not a cipher. The "SSLv2" in the cipher list represents several ciphers associated with SSLv2, not the protocol itself. In dovecot, the undocumented parameter [CODE] is used to disable particular protocols: [CODE] This exists in Dovecot v2; but I don't know if it exists in Dovecot v1.
1
2
1,647
2016-03-07T15:44:18.573
infrastructure
serverfault.com
604,903
Cannot log in to Ubuntu 14.04 LTS server after enabling root login for SSH via PermitRootLogin
When trying to log in as root (with public key) to an Ubuntu 14.04 LTS box, the OpenSSH server will just say [CODE] I have enabled root login by setting [CODE] accordingly and have also restarted SSH with [CODE] . I have also verified that this specific error would not occur if my key were wrong or not in [CODE] . Why ...
Apparently the problem lies with the seemingly innocuous [CODE] . Although it does not print any errors, it will simply not restart / reload the server, therefore root login is not yet enabled. The solution is to just use [CODE] . Duh. I know that the [CODE] way is deprecated but as long as it is still supported I'd pr...
1
2
6,967
2014-06-13T11:44:49.683
infrastructure
serverfault.com
691,114
How to stop SQL Server from logging informational lines to SQLFT log files?
I checked on a SQL Server 2012 instance recently only to see that the HDD is full and after investigating what happened it was Full Text Search informational lines filling the log files and disk space every minute. It added up to several GB of log information like the following line: [CODE] My question is how to preven...
If you can't restart the instance, you can schedule a log cleanup with sp_fulltext_recycle_crawl_log. More info: http://www.ruben-j.com/microsoft/t-sql/sql-fulltext-crawl-log/ or https://social.msdn.microsoft.com/Forums/windowsapps/en-US/b9420843-666e-4f33-b987-2624cdfa7acd/sql-server-2008r2-fulltext-logfile-sqlftlog-m...
5
4
3,582
2015-05-11T12:28:04.457
database_errors
serverfault.com
690,559
How do I force NetworkManager to update /etc/resolv.conf?
If I add a new DNS server using [CODE] , I still have to update [CODE] for the resolver to pick up the changes, right? So how do I force the update? The only way I found was restarting the network service: [CODE] . Is there a less invasive way -- a [CODE] command, perhaps?
based on http://www.certdepot.net/rhel7-configure-ipv4-addresses/ [CODE] run after mod calls, worked for me. P.S. you can use "nmcli -p connection show eth0" to see the configured vs active settings
24
22
76,262
2015-05-08T09:22:27.757
infrastructure
serverfault.com
972,735
Unable to get userName because I did not specify userName?
I am trying to run this command [CODE] and it failed with [CODE] I thought it might be due to missing profile, so I added a [CODE] parameter. [CODE] It still fails with the same error. Since I have enabled MFA, is it possible it is due to a mistyped token from the authenicator? If so, can I reset the token?
I don't see a [CODE] parameter for the [CODE] command in the documentation It should be possible to query for a user name with the [CODE] parameter. [CODE] The get-current-user command Retrieves details of the current user for whom the authentication token was generated. which might be what you are looking for. If you ...
1
2
5,642
2019-06-24T23:18:42.887
infrastructure
serverfault.com
323,155
Every value in Column 1 Needs every other value in Column 1 as a new row
I am stuck on some code. As shown in the image, I need each state to be given a new row for every other road project in the country. Ohio, for example, is given 2 new rows in the new table, 1 for each other road project in the U.S (Florida's road and New York's road)... I think this is an occasion for an aggregate func...
Is this what you need? [CODE]
2
1
25
2023-02-07T10:54:05.127
warehouse_errors
dba.stackexchange.com
146,446
Race condition in DELETE with nested query?
Is there a race condition if two processes both execute this query at (nearly) the same time? [CODE] Assume there are a variety of duplicate [CODE] 's in [CODE] , that [CODE] is (of course) an identity and primary key, and that there is no shortage of records in this table. Also assume the default isolation level (read...
It appears from empirical evidence that a race condition does exist. I've seen in the logs of an application running a query such as this where two threads each got to delete a record at the same time, and those records had the same [CODE] . If a race condition did not exist then only one thread would have gotten to de...
1
0
734
2016-08-10T21:29:57.347
database_errors
dba.stackexchange.com
202,541
Achieving Zero Downtime Deployment
I am trying to achieve zero downtime deployments so I can deploy less during off hours and more during "slower" hours - or anytime, in theory. My current setup, somewhat simplified: Web Server A (.NET App) Web Server B (.NET App) Database Server (SQL Server) My current deployment process: "Stop" the sites on both Web S...
This is a very pragmatic approach to database-backed software upgrades. It was described by Martin Fowler and Pramod Sadalage in 2003 and subsequently written up in Refactoring Databases : Evolutionary Database Design . I can see what you mean when you say that it seems sloppy, but when done intentionally and with fore...
43
16
19,460
2013-06-24T12:46:47.467
pipeline_ops
softwareengineering.stackexchange.com
672,557
Possible to have DHCP hand out different DNS server address when using different tunnel?
We have several [CODE] deployed. Currently, we have a setup where the local ASA is answering DHCP queries and is configuring clients with two DNS servers: our DR site DNS server (we use AD) and a public DNS. We need to give clients access to "the internet" when the VPN tunnel is down (this means not only packet routing...
In your situation I would simply use the ASA as a DHCP that hands out its internal IP as the DNS server, use DNS proxy to the tunnel DNS and have several public DNS's listed in the config. EG. (these commands work on c3900 equipment ios15.1, you may have to make changes to be compatible to the ASA software) [CODE] this...
5
2
3,465
2015-03-02T21:41:59.050
infrastructure
serverfault.com
976,018
IIS Application Pool taking too much memory
We have IIS running on two servers (IIS8 and 10), and encounter very high memory usage of our ASP.NET WebForms Applications lately, mostly accessed through aspx pages. What happens is that over time, our application pools consume more and more memory, until the physical memory on the server (64GB) is nearly exhausted. ...
When GC.WaitForPendingFinalizers helps, it could be a sign of memory used by threads. If you start a new seperate thread on page_load, it could use a lot of memory. Start diagnosing the problem by checking count of threads in task manager.
1
0
5,341
2019-07-20T10:00:24.970
infrastructure
serverfault.com
566,171
DNS A records disappear, but PTR records still remain
We've been having issues with DNS records dropping. Usually it is from DHCP reservations, like printers. Yesterday it was two of our main servers, also DHCP-reserved. Right now I'm looking at a normal DHCP (non-reserved) computer that is not able to be ping'd by name or nslookup'd because the A records doesn't exist, b...
Create an AD account, member of "Domain Users", set "Password never expires", in advanced DHCP properties click "Credentials..." and enter that user there. Then make the following setting in DHCP [x] Enable DNS dynamic updates according to the settings below [ ] Dynamically update DNS A and PTR records only if requeste...
1
0
5,142
2014-01-09T16:53:47.077
infrastructure
serverfault.com
115,682
MDF file size and performance
We have peaks where latency (as measured by [Physical Disk\Avg Disk Sec read] on the drive where our data file is) goes up to 0.2 sec. I immediately started suspecting the SAN while the DBA is suspecting that this is related to the fact that we currently have a single MDF file that is 5 terabytes. Does a very large MDF...
Does a very large MDF file negatively impact latency? If so what is the appropriate size? Only the size of MDF does not impact IO latency . Latency is related to your disk IO subsystem, its configuration and disk partition alignment . To find out if disk subsystem is a bottleneck, use [CODE] DMV or Capturing IO latenci...
2
2
1,469
2015-09-21T19:35:57.657
warehouse_errors
dba.stackexchange.com
628,127
PHP files loading very slowly, even if they have no PHP code
Windows Server 2008 R2 Standard IIS 7.5 PHP 5.3.28 FastCGI I have a WordPress blog in a subfolder of an ASP.NET site that has started running very slowly. After experimentation, I've found that all PHP files load slowly, even if they don't have any PHP code inside them to execute. [CODE] by itself in a text or HTML fil...
I ran into the same issue on my Windows 2008R2 server. I followed two tips that seem to have made the difference. Use the 32-bit version of PHP even if your machine is 64-bit. It is much faster Enable Output Caching in IIS for PHP files. To do this: a) Go to IIS and select your server in the Connections pane on the lef...
0
1
1,463
2014-09-12T16:41:29.070
database_errors
serverfault.com
76,180
Why can't we access SQL Server when a long query is running in Management Studio?
We have a SQL Server Database (2012 Standard edition). The database is accessed through an ASP.Net web page which displays the count of databases in different tables on page load. This work fine normally, however when we run a long query from Management Studio, the web page fails to load. It seems database does not res...
It would be impossible to say for sure without examining your web application and the SSMS query. My guess, however, is that the long query is locking tables which the web page wants to read, so the page has to wait for the query to finish. The page's timeout occurs before this happens and the page fails to load. The c...
3
4
38,222
2014-09-10T10:13:06.973
database_errors
dba.stackexchange.com
148,788
multiple rows with the same maximum value
When I run the following query, [CODE] I am getting the correct engines and seats results but not the correct manufacturer, model combination. In addition, there are multiple rows with the same maximum value for seats number which I need but just getting one result by engines/seats. I have viewed other Stack Exchange p...
Yours appears to be a "greatest N per group" problem. What you can do is get the maximum seats per engine results: [CODE] and, using them as a derived table, join them back to the source to get the rows matching the maximums: [CODE]
4
7
20,643
2016-09-04T15:14:36.470
warehouse_errors
dba.stackexchange.com
118,435
Which is the loss function used for validating a CF Recommender System?
I am developing (from scratch) a memory-based CF Recommender System based on movielens dataset . My CF RS uses a URM (User Rating Matrix) where r_ij contains the rating the user i gave to movie j (or missing). I am given a test set. Moreover I am using the k-fold cross validation for validating my model: the training s...
MAE (Mean Absolute Error) can be used to evaluate performance on hold-out data. The caveat is that MovieLens uses star ratings (1, 2, 3, 4, 5) which are measured on an ordinal scale. MAE is more commonly used to evaluate performance continuous data.
0
0
31
2023-02-10T10:28:17.303
data_quality
datascience.stackexchange.com
325,328
Iptables allow access via ssh tunnel to internal network
I am trying to restrict access on a server only to ssh by doing this. This is working nicely [CODE] However I would be using ssh port forwarding to access internal services in 127.0.0.1:port and in another internal_ip:port on a different virtual interface how can I achieve this? The command that I'm using for ssh port ...
This rule worked for me. Order is important to iptables so placing the DROPs at the end did the trick. [CODE]
2
1
7,365
2011-10-27T13:18:24.937
infrastructure
serverfault.com
851,640
Correct configuration of pcs and libvirt
So I was able to configure PCS and libvirt to work properly together. I can migrate VMs between my two nodes with no problems. All was working well until I needed to place one of my nodes in a standby mode for maintenance. It seems that my resource for the shared filesystem is being taken down before the VMs are able t...
Without being able to see your configuration, I can probably only point you to the sections of documentation that I think might be relevant... Take a look into the [CODE] option for your cloned resources in the Pacemaker documentation. It sounds like this might be what you're after. Copied from http://clusterlabs.org/d...
1
0
423
2017-05-22T20:25:48.443
data_quality
serverfault.com
271,847
compare to total, compare to percent of a main category, compare over periods e.g. month over month to get growth %
This is kind of a big question. I am looking for maybe a general direction, possible solutions to my issue, if a specific solution is impossible to give over the forum. I am working in BigQuery, however the syntax is almost identical to SQL with some functions being the exception. I am relatively new to advanced SQL an...
If anyone stumbles upon my question looking for an answer, I solved the % of total by persisting a table with totals per period (month, week, etc), then joined that table with the data table from above and used a sum(net_revenue)/max(total_revenue) and a visual filter for the period. It's not the most elegant solution,...
0
0
50
2020-07-29T09:45:22.837
warehouse_errors
dba.stackexchange.com
396,506
Umount stale glusterfs partition
I am using glusterfs on several Ubuntu servers: two of them are running glusterfs servers in replication mode. Without any clear error, the glusterfs partition became stale and the system shows this error when I try to access the stale partition: [CODE] Also, when running [CODE] on the parent folder I get: [CODE] I tri...
Try stopping the glusterfs service, first on the second node, then on the first node. For Ubuntu, the command is: [CODE] Alternatively, remove the glusterfs service from startup on both machines and reboot both. The partitions shouldn't mount on boot then, as glusterfs does this job.
3
2
11,955
2012-06-07T15:36:08.190
database_errors
serverfault.com
370,263
How to reset/flush a MediaWiki?
I have a fresh MediaWiki installation that I would like to make some mass import tests on from another wiki. I will expect that my first tries will fail, and I end up with I have inserted 500 pages with broken images and such. Question So is there a way to reset/flush a MediaWiki, so I have make a test, flush, make som...
Probably the easiest way would be to first create a [CODE] of the database while it's pristine: [CODE] ...then script a MySQL database drop: [CODE] ...followed by a mysql import: [CODE] ...to restore the database after your test completes. Might need to double-check syntax on my suggested commands; been a while and I'm...
7
7
3,650
2012-03-15T21:48:36.967
database_errors
serverfault.com
72,723
Get a prediction from the new data inputted against the model, but an error is produced, how to adapt the R code for it to work?
In the R code below, I included the sentences when looking to compare the manually classified with lexicon dictionary results by positive, negative and neutral (in matrixdata1), the algorithms results for the model produces different outcome in the tables, which is good. However, when executing.. [CODE] ..when feeding ...
This is a quite common mistake, you transformed the test and training data separately which messes with factor levels. There are multiple solutions to this: 1) Create a common transformer If you there is no "new" data but simply a test set (e.g. like in kaggle competitions or similar problems) you should create a funct...
0
1
270
2020-04-22T00:07:46.627
data_quality
datascience.stackexchange.com
217,849
Reducing MySQL RAM usage on CentOS
I have a vps with CentOS 5 (32bit) and it has 256mb of ram, although not much it is enough for me. On idle with 2 ssh connections active and httpd running it uses about 40mb of ram, but as soon as I start MySQL it shoots up to 220mb! Is there any way of optimizing the ram usage? I am only doing some light dev work on i...
First of all, how are you showing the amount of RAM free? If it's via the "free" command, note that you need to be looking at the second row under "free", not the first ( more details ). For example: [CODE] In my case I have 8GB of RAM, but nearly 7GB of that is in buffers+cache, so my true free memory is 6.9GB, instea...
1
4
4,034
2011-01-01T20:40:30.023
database_errors
serverfault.com
132,077
How to stop OSX MySQL filling up error logs
I've noticed about every second, a new line the mysqld error log noting a login failure. The user isn't always the same, but it consistently happens every second when mysqld is running. I'd like to turn this behavior off or prevent it from logging. I suspect this has something to do with launchd / launchctl . Suggestio...
[This question is almost a year old, but anyways I just came across it while investigating the same issue, and although the answer is probably no longer relevant for you, it might be for someone else reading this.] This can happen when using the standard MySQL installation including the MySQL preference pane. When open...
3
6
423
2016-03-12T17:30:37.837
database_errors
dba.stackexchange.com
907,807
how to prevent image hotlinking in nginx?
I am trying to implement image hotlink protection problem in nginx and I need help. I have a huge issue of my site's images being submitted to social networks like StumbleUpon with a direct link like http://example.com/da.jpg now i want to block access to them but I cannot implement hotlink prevention in my nginx.conf ...
Perhaps your images need a root location too. [CODE]
3
5
7,236
2018-04-16T08:20:07.807
infrastructure
serverfault.com
310,748
Receiving errors without engaging in excessive communication when using sockets
I'm currently writing a program that communicates with a server over TCP sockets. I originally planned for the communication to include a message confirming successful communication at the end of correspondence. Either the server and the client would wait for a response after each communication, depending on who initia...
There are four ways to approach client-server communications: Synchronous: every request receives a response of some form. In this approach, the client will wait for a response after every request, and it will expect every request to have a response. This introduces delays because the client (or server) could potential...
1
3
104
2016-02-22T11:47:32.750
api_errors
softwareengineering.stackexchange.com
257,473
How to get Linux udev to play nice with Hyper-V IC synthetic network driver
I managed to get the Debian 6.0.1 to work with the Microsoft Hyper-V synthetic drivers, thanks to this question . However, if I don't remove the entry for the synthetic ethernet card from [CODE] on every boot, the VM won't boot the next time as there is a [CODE] (Recursive fault) - [CODE] How do I fix this? EDIT : [COD...
I think try this, based on a Debian forum post [CODE]
6
2
2,985
2011-04-08T18:39:49.803
infrastructure
serverfault.com
924,421
Postfix, Exchange Online - Copy specific e-mails to another mailbox received during the night
We used postfix + sieve before, but we migrated to Exchange Online, therefore we need another solution, postfix is still running as a mail gateway. We need to copy e-mails received from a specific e-mail address (mail@example.com) with a specific subject (like "**PROBLEM") from 6pm to 8am and on saturdays/ sundays to a...
I managed to find another solution: postfwd (Postfix firewall daemon). At least when it comes down to sender and time checks, because it cannot match subject, body, etc.
0
0
48
2018-08-01T11:13:33.697
infrastructure
serverfault.com
880,055
Bad gateway on 2 sites after Certbot changed the Nginx site-conf file of one of them
I experience bad gateway on 2 sites after Certbot changed the Nginx site-conf file of one of them. No errors all in [CODE] . Only this comes up in [CODE] : 2017/10/24 15:40:47 [error] 27439#27439: *125 connect() failed (111: Connection refused) while connecting to upstream, client: 66.249.69.71, server: domain.tld1, re...
The main problem was that the CGI directives regarding my site (responsible for PHP-dependent data processing), as appears in my site-conf file, weren't as they should be after implementing SSL. This is the new setting that works: [CODE] Regarding the error I had with the detault, just go to sites-enabled and delete th...
0
0
528
2017-10-24T15:50:00.433
api_errors
serverfault.com
978,318
High availability docker swarm
I have a Docker swarm cluster running on several servers (nodes). Docker swarm is using round robin to serve requests to my services and this is working well no matter which server receives a request. Now I wonder how to route a URL to this setup to have it highly available. I use Euro DNS (eurodns.com) and set the A r...
Round robin DNS should work for most scenarios, though there will be a delay when requests to one IP timeout and the client eventually retries the next IP in the list. What it will not help with is a partial failure where the host is responding to network requests but the application (e.g. docker) is not responding or ...
0
1
655
2019-08-07T14:54:07.350
pipeline_ops
serverfault.com
284,821
Suggestions for HTTP load balancers for linux?
Possible Duplicate: Software http load balancer? Came across few load balancers like Pound( http://www.apsis.ch/pound/ ) , HAProxy ( http://haproxy.1wt.eu ) and BalanceNG ( http://www.inlab.de/balanceng/index.html ). Any suggestions on choosing a good load-balancer ?
If you are particularly looking to load-balance http traffic, then an http-specific load balance (like Pound) is going to be more flexible than a generic TCP load balance (like ipvs, or balanceng). An http load balance can make decisions based on http headers, which can be particularly useful in linking client cookies ...
1
2
758
2011-06-28T10:52:25.790
data_quality
serverfault.com
34,529
Exchange 2007 can not send email to the Internet
We are currently in the beginning stages of migrating from Exchange 2003 to Exchange 2007. We have got to the point where internal mail between the two systems is working perfectly with all of our testing accounts, the problem is now that Exchange 2007 is not able to send email to external domains. Seems like an easy e...
Going back through my questions I realized this one was never answered. Turns out that not a single Exchange 2003 server had an explicitly defined send connector and were all using the default one. As soon as a send connector was explicitely defined within the Exchange Org all mail started using that.
1
0
12,813
2009-07-01T15:15:58.007
infrastructure
serverfault.com
614,890
Can't run AWS CLI from CRON (credentials)
Trying to run a simple AWS CLI backup script. It loops through lines in an include file, backs those paths up to S3, and dumps output to a log file. When I run this command directly, it runs without any error. When I run it through CRON I get an "Unable to locate credentials" error in my output log. The shell script: [...
If it works when you run it directly but not from cron there is probably something different in the environment. You can save your environment interactively by doing [CODE] And do the same thing in your script [CODE] And then [CODE] and see what matters. Things like [CODE] are the most likely culprits.
36
24
51,437
2014-07-23T15:51:59.227
database_errors
serverfault.com
162,141
Need an anonymizer for my site
I have a website that I want to make public. However I don't want people to know its real location. Two solutions that could work were: To find a free webhosting and store the web interface part there, and then keep the database and non-interface logic on my real site. However it seems like all free hostings do not let...
Solution 1 . would easily work. You need to open your database to outside access (bind-address for mysql). And then modify your web interface (in whatever language you wrote it) to use the IP address of your database 's server. The possible drawbacks are that it can be slow to communicate with mysql this way, and the c...
0
0
206
2010-07-20T10:25:22.400
infrastructure
serverfault.com
216,464
SQL How to Convert Single Tenant Databases to a Multitenant Database
We have a legacy application. For some reason, someone decided to create a database for each customer. So we have 500+ databases with the same schema. I would like to convert into One multi-client database. The Original customer database does not have CustomerId. New Singular database does. We are thinking of replacing...
sql-server-2016 This can be made to work using [CODE] (new in SQL Server 2016). In previous versions [CODE] could be used, but it is less robust (cannot be read-only, only one slot per session). Example First, set a [CODE] on the underlying table's [CODE] column: [CODE] Then define the view as follows: [CODE] Each sess...
2
5
1,220
2018-09-01T02:42:23.667
api_errors
dba.stackexchange.com
895,572
Nginx server can not start
My nginx server can't start anymore after I killed its process through [CODE] . Now everytime I try [CODE] , i get this error [CODE] When I navigate to [CODE] , the directory does not exist. Should I create it manually?? Am in macOs sierra.
I solved it by creating the [CODE] file manually.
0
1
1,499
2018-02-04T05:31:25.443
infrastructure
serverfault.com
310,808
pg_dump on heavily written production db causing queries to hang
Trying to migrate our existing DB. There are no followers or existing backups that are available to us (they are on our cloud solution, but no available for download). So our only option is to run pg_dump on our prod table. It is very heavily written to and is roughly 700GB in size. [CODE] Running the following will be...
We ended up just forking the database on the service for a single day, backing up on that as , and then shutting it down.
1
0
542
2022-04-10T04:27:33.527
database_errors
dba.stackexchange.com
239,552
how does openvpn decide which interface to get IP addrs from
Using ubuntu 10.04 on both ends. We have a client and server machine on the SAME network attempting to make a vpn connection. We use the config files from here and made minimal changes. The server and client start and seem to connect without any trouble. The server looks like: [CODE] On the client side the connection l...
If a client has more than one interface it decides where to route packets based on the routing table. Run [CODE] on the command line. and you'll see the routing table, eg: [CODE] You can see that the 192.168.161.0/24 subnet is on tun0, which is the openvpn connection. eth3 is the LAN connection with the subnet 192.168....
0
1
1,021
2011-02-24T03:25:10.433
infrastructure
serverfault.com
853,895
Doesn't receive email from other mail servers
I really need your help. I am trying to set up first time my own mail server using Postfix, Dovecot IMAP/POP3 and MySQL backend on a Ubuntu server. I can successfully receive and send mail to my local server, However I can only send mail to to other mail servers like gmail and outlook but unable to receive. and always ...
Troubleshooting Problems with Postfix, Dovecot, and MySQL This is an excellent guide to troubleshoot Postfix and Dovecot problems, I have followed it's instruction to find out what is the problem. Anyone who is trying to set up mail server for the first time like me must follow this guide to know how to debug problems ...
-2
0
537
2017-06-04T13:51:44.450
api_errors
serverfault.com
761,833
Postfix Hostname domainbased
I would like to excuse in advance, if my question has already been answered before but im going crazy since a week now... I'm not new to this but after a while in another job, my "skills" are totally rusty. At the moment im running a vServer with Debian 7.9 Plesk 12.5 was preinstalled, postfix & dovecot also. I don't w...
Pick a domain to use for email (with FCrDNS) and stick with it, use spf on all domains to authorize the ip, your problem is ehlo and mail from do not match and you haven't configured spf to authorize the other the primary domain to send on behalf of others. Same way Google apps or office 365 do, you don't see them whit...
1
2
89
2016-03-05T18:06:30.813
infrastructure
serverfault.com
905,297
ssh remote command: Killed by signal 15
script: [CODE] with output: [CODE] I have used the [CODE] to capture the signal, but still not work? Any help will be appreciated!
I think what's happening here is that the [CODE] is also matching the shell running that command, since it will find the string "/usr/bin/nmon" in the full command-line and you specified -f to look for the string in the whole command-line (and not only the process name...) There are many things incorrect in your script...
0
1
4,471
2018-03-30T03:27:18.053
infrastructure
serverfault.com