Progress on Maatkit bounty, part 4

… I didn’t get two-way sync done, and I didn’t get the Nibble algorithm done. That much I expected. But I also didn’t get the current work released tonight because I’m paranoid about breaking things. I’m trying to go through all the tools and write at least a basic test for them to be sure they can do the simplest “unit of work” (such as mk-find running and printing out that it finds the mysql.columns_priv table).

It’s good that I’m doing this. I found that mk-heartbeat suddenly doesn’t work on my Ubuntu 7.10 laptop. It goes into infinite sleep. Can anyone repro this and/or diagnose? The same code works fine on Gentoo servers at work, and I have heard no complaints.

Update the problem is the combination of sleep() and alarm(), which I inherited in the code from the contributors. I even had a comment in the code about it not being safe in general, but I assumed it would work OK since there was no argument to sleep() (infinite sleep). But it doesn’t; the results are undefined and system-dependent. I re-implemented this code without using alarm() and will release it soon.

Hopefully I’ll be able to release something very soon. Release early/often is fine, but “knowingly release brokenness” isn’t in my code of conduct :)


About The Author

Baron is the founder and CEO of VividCortex. He is the author of High Performance MySQL and many open-source tools for performance analysis, monitoring, and system administration. Baron contributes to various database communities such as Oracle, PostgreSQL, Redis and MongoDB.


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