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Re: Server 8.0 is extremaly slow ERIC GENDRON
Posted by: Peter Brawley
Date: December 19, 2019 12:55PM

Eric,

The thread hopelessly conflates multiple discussions, apologies for not catching that in time.

It's a small system but 10.5G RAM is available to MySQL, it's using < 2GB, innodb_buffer_pool_size is best grown up to about 7GB.

And, some queries need optimising---for help with that, post the queries, the results of Explain & Explain Analyze on them, plus Show Create table results for tables referenced in each query.

MySQL version                           8.0.18          
Slow queries/sec                        0               Find & optimise those queries
Queries not using indexes               0               
Queries needing full table scans/sec    0.0005          Find & optimise those queries
InnoDB buffer pool inefficiency         0.0125          GROW INNODB_BUFFER_POOL_SIZE IF > 2% OR < 70% OF RAM                                               
InnoDB page reads and buffer pool       0.024           
InnoDB log file thrashing               12              Best is near 0.5; grow innodb_log_file_size 
                                                        if well under 0.5, shrink if much larger
Time between InnoDB log rotation        3:54:05         Grow log size if < 30 min, shrink if > 60 min
InnoDB buffer pool reads / sec          0.0047          If high, increase Innodb_buffer_pool_size up to 70% of RAM
Est. best InnoDB log file size          32MB            Average hour of writes rounded up to 32MB boundary
MyISAM key buffer size                  8MB             Pre-8.0 MyISAM system tables need about 40MB
MyISAM query cache spills / sec         0               
MyISAM query cache hits / sec           0               
MyISAM cache miss ratio                 4.55            If > 10, grow key_buffer_size
MyISAM key write ratio                  0               Much higher than 1 suggests a disk write bottleneck
MyISAM key read rate                    0               Should be high when the buffer is full
MyISAM query cache hits/inserts         0               
Temp tables created/sec                 0               If > 20, find the queries responsible and optimise them, 
Temp tables created on disk/Questions   0               If > .05, try growing join_buffer_size, 
                                                        optimise responsible queries, 
Temp tables created on disk/sec         0               If high, grow tmp_table_size,max_heap_size. Avoid Blobs,
                                                        use HEAP tables in queries
Database changes / connection           0.09            Use db.table syntax
Processes/connection                    0.36            If high, grow thread_cache_size
Files opened/sec                        0               If > 5, increase table_open_cache
Queries/sec                             0               Thousands is busy: you may need better hardware
Writes/sec                              0               If, over 50/sec, better disk hardware may be needed
Insert statements/sec                   0               
Inserts/sec                             0.06            Can be up to 20K/sec with efficient memory use, see here
Next table row requests/sec             449             QUERIES NEED OPTIMISING ESP. WITH COVERING INDEXES
Sampling time                           7:46:18         If less than 2h in a typical use period, re-do
Max MySQL RAM use                       1.9GB           Must be < RAM available to MySQL
Available RAM                           10.52GB         If less than Max MySQL memory use, more RAM needed                                               

InnoDB basic stats
  innobuffpool  bytes read/sec  reads/sec     bytes/read  bytes written/sec  writes/sec   bytes/write    rollback %  buffpool free %
       8MB              0            120          16261           24            0           13364           0             43



Edited 1 time(s). Last edit at 12/19/2019 12:55PM by Peter Brawley.

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October 02, 2019 06:41AM
Re: Server 8.0 is extremaly slow ERIC GENDRON
December 19, 2019 12:55PM


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