Diagnosing Random MariaDB Freezes
9 points by ankush
9 points by ankush
There's very little content here, and nearly no information about the actual solution. There are no stats on what the results of each attempt were. There's no quanitfication of database stalls, or analysis of why it's a stall rather than a slowdown. Basically, this post is "Stats queries are too big for cache, and that causes things to stall while opening tables around 2800 iops. We got this number, somehow, through EBPF. We stopped doing stats queries."
Someone took 4 bullet points and expanded it into paragraphs of empty text with an LLM. This is an antisocial denial of service on people's attention.
I'd like to request that we, like reddit's /r/programming, make any llm-generated content a bannable offense.
Good debugging story. The issue with monitoring being made ineffective by the very performance bug that it was intended to catch, is mildly terrifying.
The tool reads only the required metadata directly from InnoDB files, with safeguards:
Controlled concurrency for reading table files
Huh... how do you correctly read directly from InnoDB files while transactions are going on? That seems like a big thing but they didn't talk about it.
That parser reads the FSP header and a few metadata pages to estimate table size. We may read some stale information, but our only goal is to get the most accurate table size. Since pages may not be flushed yet, the result can have a small error. That is acceptable for our use case. We are still experimenting, but so far hasn't faced issue.