I recently, blindly, updated to Percona 5.6 via the repos. I’m not running a very sophisticated database (it’s a small user group (<10) mostly for displaying timed data that can be inputed via an php interface). I have a few databases with the average size of less than a MB, the most users that are ever connected at the same time is about 5.
My server is a dedicated VSS with 1GB of ram. Percona 5.5 would use around 200-300MB of ram total when running.
However, after updating to Percona 5.6, when the server starts it instantly uses about 450MB of Physical memory and 1.5GB of virtual memory. These amounts seem to be stable once the program launches.
I’ve optimized all my settings and there shouldn’t be a problem: from MySQLTuner:
Maximum possible memory usage: 338.9M (22% of installed RAM)
Highest usage of available connections: 0% (1/151)
Key buffer size / total MyISAM indexes: 8.0M/45.0K
Query cache efficiency: 0.0% (0 cached / 26 selects)
Query cache prunes per day: 0
Sorts requiring temporary tables: 0% (0 temp sorts / 1 sorts)
Temporary tables created on disk: 10% (10 on disk / 97 total)
Thread cache hit rate: 94% (1 created / 18 connections)
Table cache hit rate: 62% (111 open / 178 opened)
Open file limit used: 0% (48/470K)
Table locks acquired immediately: 100% (70 immediate / 70 locks)
InnoDB data size / buffer pool: 864.0K/128.0M
using pmap i see there are a bunch of 10MB blocks of memory allocated, which makes sense, however, I see 2 huge chunks of memory allocated for reasons unknown, which I think are the problem, I cut out some of the early address because i hit the posting character limit:
it’s just anon memory allocation, which I don’t understand why it needs to allocate so much. Seems like a bug, any help would be GREATLY appreciated, I would like to get my server down to 200-300MB again.
I can also confirm this problem. I went to a fresh 5.6 install (not an upgrade) and imported the data that was dumped from mysql. Percona is performing well, but memory consumption increases (slowly) monotonically and doesn’t come back down. This is independent of actual load.
Dear Percona,
I believe that this is a major issue with your product and it should be addressed quickly.
Could you inform us about the progress of analyzing/fixing of this bug?
I could add, that in my case it was Debian wheezy x64 on OpenVZ VPS server (kernel 2.6).
Just checking in on this. Wanted to add I’m using
Based on the number of views this thread has (more than any other post), I’m thinking a lot more people are having this problem.
There is absolutely nothing we can do right now to alleviate this issue, the users are helpless, please update us.
Rogers,
“I believe that this is a major issue with your product and it should be addressed quickly.”
Performance schema is a functionality coming from upstream MySQL developed by Oracle crew, we just use exactly the same functionality in Percona Server.
Do you notice smaller memory footprint in MySQL 5.6 vs PS 5.6? If yes, let us know.