Graphing on-demand Linux system performance parameters

Current servers are way more powerful than we could have imagined before. With quad-core CPUs, even the simple dual-socket servers contain lots of horse-power. Remember our attitude towards CPU power five years ago, and see that we’re way beyond our needs.

When modern servers are equipped with at least eight cores, other, non-CPU related issues become noticeable. Storage, as always, remains a common bottleneck, and, as an increase in expectations always accommodate increase in abilities, memory and other elements can be the cause for performance degradation.

sar‘ is a known tool for Linux and other Unix flavors, however, understanding the contexts within is not trivial, and while the data is there, figuring what is relevant for the issue at hand becomes, with more disk devices, and more CPUs, even more complicated.

kSar is a simple java utility which makes this whole mess into a simple, readable graphs, capable of being exported to PDF for the pleasure of the customers (where applicable). It parses existing sar files, or the extracted contents of ‘sa’ files (from, by default, /var/log/sa/). It is a useful tool, and I recommend it with all my heart.

Alas, when it comes to parsing ‘sa’ files, you will need, in most cases, either to export the file into text on the source machine, or use a similar version of sysstat tools, as changes in versions reflect changes in the binary format used by sar.

You can obtain the sysstat utils from here, and compile it for your needs. You will need only ‘sar’ on your own machine.

An important note – you will not be able to compile sysstat utils using GCC 4.x. Only 3.x will do it. The error would look like:

warning: ‘packed’ attribute ignored for field of type `unsigned char…

followed by compilation errors. Using GCC version 3.x will work just fine.

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