higher TCP ICW – real world tests
this post inspired me to check how much performance can we gain by just upgrading to more recent kernel on the internet-facing proxy servers at work.
tech
extracting single database from a [large] mysqldump
extracting the whole database: sed -n '/^-- Current Database: `databaseName`/,/^-- Current Database: `/p' /path/to/the/fill/dump.sql > output.sql single table: sed -n '/^CREATE TABLE `tableName`/,/^\-\- Table structure for table /p' /path/to/the/fill/dump.sql > output.sql [via this blog]
cloning the server using rsync
braindump of things to do/directories not to copy when cloning physical debian to a vm using rsync
switching reverse proxy from apache2 to nginx
i’ve been planning for a while to move away from apache2 as a reverse proxy in front of java appservs and start using nginx. i had two reasons: nginx can handle much better large number of concurrent connections [something we can make use of if we start using long-poll/comet], nginx gives more control over buffering ... Read More
new sphinx, new connector/j headaches
sphinx 2.0.3 is out; and as new drama of getting mysql’s connector/j begins. i did not figure out [yet] any way of making both work using the latest 5.1.18 connector, but at least i’ve managed to convince one that i use now [ 5.1.15 ] to work with sphinx. what works: mysql-connector-java-5.1.13-bin.jar but.. only if ... Read More
excluding some mysql queries from the slow query log
i keep close eye on the mysql-slow.log log of queries that take more than 1s to execute. but at the same time i know about few house-keeping queries that are executed few times per day that by design take longer to execute [eg table checksums]. i don’t want those queries to ‘pollute’ the slow query ... Read More
ossec-syscheckd(1702): INFO: No directory provided for syscheck to monitor; Segmentation fault
i’m playing around with ossec 2.6. i’m trying to set up server for agentless monitoring of multiple linux boxes. after installation [where i answered no for most of the question] i’ve run into the following problem: to make things work and not segfault on config generated by the installer i had to modify /opt/ossec/etc/ossec.conf and ... Read More
java7, XMLEncoder problems
for the last few days i’ve been looking into java7… it surely seems faster. but also some of my old code broke when run under it.
ghettovcb hangs while removing the snapshot
i’ve upgraded few vmware esxi 4.1 servers with the latest patches and… obviously something got broken. i use ghettoVCB script to take weekly snapshots of the vms. scripts hanged last night on all servers.
ilo
i take care of one HP server with ILO remote access card. but recently i started having problems with using web applet to connect to it.
kindle 3g
few months ago i bought kindle 3g. below what’s good and what’s bad about it.
“boot failed: not a bootable disk” after migrating kvm image
i’ve migrated some vm from qemu-kvm-0.12.4 to qemu-kvm-0.12.5 and … got unpleasant surprise – unbootable machine.
mysql 5.1 – turning on/off query logging on the fly
i dont run query logging – more to avoid running out of the disk space on /var/log than for the performance reasons. but from time to time it’s good to be able to turn logging on to see what’s going on. in 5.1 and later versions it’s possible without restarting the mysqld.
mysql circular / master-master replication
i’ve been playing for a while with mysql circular replication; here are some notes from setting it up.
vlans over bridged interface
the lenny/squeeze way.
mysql connector/j 5.1.16 + sphinxql 0.9.9 = MySQLNonTransientConnectionException
most recent connector/j – 5.1.16 does not seem to work with sphinx search 0.9.9. i did not find [yet] actual cause of the problem but going back to 5.1.15 solved the problem for now.
innodb_stats_sample_pages to save a day
i’ve run into nasty instability in mysql’s query execution plan joining few tables with 10s of millions of rows. mysql 5.1’s innodb_stats_sample_pages seem to solve the problem.
[pl] asmax ar 901 + netia dsl z 8 publicznymi adresami ip
pare informacji o tym jak skonfigurowac publiczna podsiec /29 na routerze netii asmax ar-901.
lenny to squeeze upgrade – aftermath
few problems/differences i’ve noticed after upgrade of debian.
opera mini 6 + rss feed
opera mini is a great mobile web browser. new release just got out; yet rss [quite an important features for me] seems to be a sort of neglected functionality. here’s how to get it to work in v6.