MySQL Performance: MySQL => Innodb 'Free buffers' going to 0 and system crashing

Innodb 'Free buffers' going to 0 and system crashing [message #397]

Wed, 22 November 2006 10:49

lidram
Messages: 2
Registered: November 2006
Location: Malta (Europe)

Junior Member

Hi,

i have a mysql 5.0. engine running an innodb db with roughly 3GB of data and 2GB of indexes. It has 5GB of memory available, running on Solaris9.

I noticed that the mysql process starts using the amount of memory as the value innodb_buffer_pool_size in my.cnf (ie 2GB), but after some time starts ramping up and eventually hogs all the memory:

PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
18975 mysql 2900M 1025M cpu2 30 0 1:32:12 16% mysqld/18

PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
28266 mysql 4793M 4421M sleep 59 0 41:43:33 2.5% mysqld/19

I also noticed that the 'Free Buffers' reduced with time, and when it becomes 0 mysql stops serving queries.

----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 2373583706; in additional pool allocated 19627008
Buffer pool size 131072
Free buffers 1
Database pages 128099
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages read 870652, created 648834, written 1617115
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 1000 / 1000

1) Why does the memory ramp up? It looks like a memory leak?
2) What are the buffers in the 'buffer_pool_size' used for and how?
3) How can i clear these buffers?

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