Posts Tagged ‘central server’

Configure rsyslog buffering on Linux to avoid message lost to Central Logging server

Wednesday, January 13th, 2021

Reading Time: 2minutes

rsyslog-Centralized-Logging-System-using-Rsyslog_logo

1. Rsyslog Buffering

One of the best practice about logs management is to send syslog to a central server. However, a logging system should be capable of avoiding message loss in situations where the server is not reachable. To do so, unsent data needs to be buffered at the client when central server is not available. You might have recently noticed that many servers forwarding logs messages to a central server do not have buffering functionalities activated. Thus I strongly advise you to have look to this documentation to know how to check your configuration: http://www.rsyslog.com/doc/rsyslog_reliable_forwarding.html

Rsyslog buffering with TCP/UDP configured

In rsyslog, every action runs on its own queue and each queue can be set to buffer data if the action is not ready. Of course, you must be able to detect that "the action is not ready", which means the remote server is offline. This can be detected with plain TCP syslog and RELP, but not with UDP. So you need to use either of the two. In this howto, we use plain TCP syslog.

– Version requirement

Please note that we are using rsyslog-specific features. The are required on the client, but not on the server. So the client system must run rsyslog (at least version 3.12.0), while on the server another syslogd may be running, as long as it supports plain tcp syslog.

How To Setup rsyslog buffering on Linux

First, you need to create a working directory for rsyslog. This is where it stores its queue files (should need arise). You may use any location on your local system. Next, you need to do is instruct rsyslog to use a disk queue and then configure your action. There is nothing else to do. With the following simple config file, you forward anything you receive to a remote server and have buffering applied automatically when it goes down. This must be done on the client machine.

# Example:
# $ModLoad imuxsock             # local message reception
# $WorkDirectory /rsyslog/work  # default location for work (spool) files
# $ActionQueueType LinkedList   # use asynchronous processing
# $ActionQueueFileName srvrfwd  # set file name, also enables disk mode
# $ActionResumeRetryCount -1    # infinite retries on insert failure
# $ActionQueueSaveOnShutdown on # save in-memory data if rsyslog shuts down
# *.*       @@server:port

Make daily Linux MySQL database backups with shell script

Thursday, May 23rd, 2013

Reading Time: 2minutes

Creating database backup with MySQL with mysqlbackupper and mysqlback shell scripts easy create mysql backups

Some time ago, I've written a tiny shell script which does dumps of Complete (SQL Script) MySQL databases. There are plenty of ways to backup MySQL database and plenty of scripts on the net but I like doing it my own way. I have few backup scripts. I prefer script database over keeping binary logs, or using some un-traditional backup methods like backing all binary data in /var/lib/mysql.

One was intended to backup with mysqldump whole database and later upload to a central server running tsh (shell). Using tsh maybe not the best method to upload, but the script can easily be modified to use ssh passwordless authentication as a method to upload.

I'm not a pro shell scripter, but MySQLBackupper script can be used as useful for learning some simple bash  shell scripting.

To use the script as intended you will have to build tsh from source. Tsh is in very early development stage (ver 0.2) but as far as I tested it before some years it does great what it is intended for. You can  MySQLBackupper.sh script from here.
Earlier, I used MysqlBackupper.sh to upload all SQL dumps to /backups directory on central backup storage server, thus I had written secondary script to classify uploaded backups based on backup archive name. Script used is mysqldumps-classify.sh and can be viewed here. Though this way of making backups, needs a bit of custom work for managing backups up to 10 / 20 servers it worked well.

I have written also another mysqlbackup script which is much more simplistic and only dumps with mysqldump and stores copies on hard disk in tar.gz archive. You can download my other simple mysqkbackup.sh here.

Only inconvenient thing about above scripts is they dump all SQL databases. Hence whether necessary to get content for single database from (complete) All database SQL (script backup), I use SED (stream editor) one liner script.

It is interesting to hear how others prepare their MySQL db backups.