CODEWITHSUNDEEP
mysqlmemorydocker
timetofly
timetofly

Reputation: 3077

MySQL is using way more memory that it is configured to within a Docker container

I have read a number of answers here on SO, as well as gone through this excellent post from Percona. My max innodb_buffer_pool_size is 50MB, with one instance. Query cache is off, and MYISAM is pretty much not in use.

Relevant output of pt-mysql-summary:

   # InnoDB #####################################################
                  Version | 5.6.35
         Buffer Pool Size | 50.0M
         Buffer Pool Fill | 5%
        Buffer Pool Dirty | 0%
           File Per Table | ON
                Page Size | 16k
            Log File Size | 2 * 48.0M = 96.0M
          Log Buffer Size | 8M
             Flush Method | 
      Flush Log At Commit | 1
               XA Support | ON
                Checksums | ON
              Doublewrite | ON
          R/W I/O Threads | 4 4
             I/O Capacity | 200
       Thread Concurrency | 0
      Concurrency Tickets | 5000
       Commit Concurrency | 0
      Txn Isolation Level | REPEATABLE-READ
        Adaptive Flushing | ON
      Adaptive Checkpoint | 
           Checkpoint Age | 0
             InnoDB Queue | 0 queries inside InnoDB, 0 queries in queue
       Oldest Transaction | 0 Seconds
         History List Len | 0
               Read Views | 0
         Undo Log Entries | 0 transactions, 0 total undo, 0 max undo
        Pending I/O Reads | 0 buf pool reads, 0 normal AIO, 0 ibuf AIO, 0 preads
       Pending I/O Writes | 0 buf pool (0 LRU, 0 flush list, 0 page); 0 AIO, 0 sync, 0 log IO (0 log, 0 chkp); 0 pwrites
      Pending I/O Flushes | 0 buf pool, 0 log
       Transaction States | 1xnot started

# MyISAM #####################################################
                Key Cache | 8.0M
                 Pct Used | 20%
                Unflushed | 0%

# Query cache ################################################
         query_cache_type | OFF
                     Size | 0.0
                    Usage | 0%
         HitToInsertRatio | 0%

There are no connections/processes. Yet top shows:

PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
    1 mysql     20   0  973460 465988  12780 S   0.0 11.5   0:00.85 mysqld

Almost 500MB of RAM! According to all my memory settings, it shouldn't be more than maybe 60MB or 70MB.

What am I missing here?

Upvotes: 1

Views: 1407

Answers (1)

gbolo
gbolo

Reputation: 519

you should disable the performance schema among other tweaks. this is what I use, which produces a mysqld that consumes less than 100MB:

https://github.com/gbolo/vSummary/blob/master/docker/my.cnf

[mysqld]
performance_schema = 0
skip-host-cache
skip-name-resolve
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr
datadir     = /data/mysql/data
tmpdir      = /tmp
skip-external-locking
max_connections     = 100
connect_timeout     = 5
wait_timeout        = 600
max_allowed_packet  = 16M
thread_cache_size       = 128
sort_buffer_size    = 4M
bulk_insert_buffer_size = 16M
tmp_table_size      = 32M
max_heap_table_size = 32M
myisam_recover_options = BACKUP
key_buffer_size     = 128M
table_open_cache    = 400
myisam_sort_buffer_size = 512M
concurrent_insert   = 2
read_buffer_size    = 2M
read_rnd_buffer_size    = 1M
query_cache_limit       = 128K
query_cache_size        = 64M
slow_query_log_file = /data/mysql/logs/mariadb-slow.log
long_query_time = 10
expire_logs_days    = 10
max_binlog_size         = 100M
default_storage_engine  = InnoDB
innodb_buffer_pool_size = 256M
innodb_log_buffer_size  = 8M
innodb_file_per_table   = 1
innodb_open_files   = 400
innodb_io_capacity  = 400
innodb_flush_method = O_DIRECT


[mysqldump]
quick
quote-names
max_allowed_packet  = 16M

[isamchk]
key_buffer      = 16M

Upvotes: 1

Related Questions