Admin tips

What’s Redis?

Redis is an advanced key-value store. It is similar to memcached but the dataset is not volatile, and values can be strings, exactly like in memcached, but also lists, sets, and ordered sets. All this data types can be manipulated with atomic operations to push/pop elements, add/remove elements, perform server side union, intersection, difference between sets, and so forth. Redis supports different kind of sorting abilities.

Also it is really fast – 110000 SETs/second, 81000 GETs/second at Xeon X3320 2.5Ghz Linux 2.6.x server. I believe that everything should be monitored so I’ve written redis monitoring plugin for Munin. It allows to monitor some of the values such as:

• connected clients
• requests per second
• connections per second
• used memory

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If you’ve already tried to create RPMs for Sun JDK at CentOS/Fedora you know that ODBC dependencies get linked incorrectly for JDBC RPM (JDBC is used to create MySQL/PostgreSQL/etc connections using Java applications)

As the result if you will try to install JDBC RPM you’ll see the following message:
libodbcinst.so() is needed by java-1.6.0-sun-jdbc-1.6.0.14-1jpp.i586
libodbc.so() is needed by java-1.6.0-sun-jdbc-1.6.0.14-1jpp.i586


If you don’t need database support at Java applications you still can install all other RPMs that were created during your build and ignore java-1.6.0-jdbc-* RPM.

At my case DB support was necessary so I used Google and found this solution. You will only need to install nosrc RPM and to slightly modify the spec file.

If you haven’t got luck with SPEC modifying all of Sun JDK 1.6.0 update 14 RPMs (CentOS 5.3 i386) could be downloaded here
Possibly I’ll build them also for x86_64 some day.

I don’t really know why there is still no memcached-1.4.2 at rpmforge (Dag Wieers repository).

Our programmers were needed exactly 1.4.2 version.
I hadn’t find any EL5 RPM so I had have to build my own.
CentOS 5.3 (both i386 and x86_64) RPM could be downloaded here (memcached-debug is not included)