Rick James wrote:
> Is max_allowed_packet = 1M on both Slave and Master?
> server_id is different?
> Master did not crash?
> Using MyISAM or InnoDB??
>
Increased Max_allowed packet on slave servers.
Master 1M - Slave 12M (because warnings, high loads)
server id is unique on every server
master did not crash, works fine.
MyISAM tables. InnoDB not used.
> On 8/17/10 8:40 AM, Andrej Pintar wrote:
>> Hello friends,
>>
>> *Today I decided to tune MySQL Master Server by adjusting some
>> variables:*
>> -join_buffer bigger (1-2MB)
>> -read_buffer bigger (8MB)
>> -read_rnd_buffer bigger (2MB)
>> -connect_timeout bigger (20-25)
>> -tmp_table_size 4x bigger (512MB)
>> -sort_buffer bigger (2MB)
>> -table_cache 2x bigger (512)
>>
>> Server* is not* on heavy load so I can afford high values.
>> 4cpu-8cores, 8gb ram, sas 15k hdd.
>> Local application installed.
>>
>> I tested MonYog for monitoring and I use MySQL report on linux.
>> Both
>> installed on Linux. Before I could expect MySQL
>> improvement after service restart and wait at least a day to see
>> status variables Replication crashes.
>>
>> *The error was like few years ago. Error description:*
>> Error 1236 on slave. Could not read binary log (corrupt)?
>> SLAVE_IO is on not running. SLAVE_SQL running.
>> MySQL master version : 5.0.51b win64
>> MySQL slave version: 5.0.51b win36 and 5.0.67 (linux x64)
>>
>> Since nothing has cheanged at least a year and I mostly do not
>> restart replication for at least 6 months period. This occurred
>> an hour or more after tunning.
>>
>> Now my question is do some of these variables really affect
>> replication?
>>
>> *Slave servers are connected to master using following:*
>>
>> MASTER (3306) - SERVER01 (on direct line, static ip) - 3309 (ip
>> filter, using CCproxy) - SLAVE (global, location DE)
>>
>> Master and Server01 are inside the company on a LAN (1Gbps). Direct
>> Line speed is 5/5 Mbps. SLAVE is 100Mbps (Web Server). I doubt that its
>> related to network problems because it works perfect.
>> Slave connects to proxy on 3309, Server01 forwards request to
>> MASTER.
>>
>> * Reason for optimize:*
>> -table locks, waited(Select queries), state DEAD displayed in
>> process list - query does finish in a lot of time, concurrent query's
>> while user presses F5 in browser makes it a little worse
>> -table scans
>> -joins
>> -tryed to improve server by tunning because of those reasons
>>
>> -query cache not used because of big query's
>> -index hit rate 99,96%
>>
>> -slow query time: *200s,* lock times:* 60s*
>>
>> * Query status:*
>> -lot's of slow queries which I can't rewrite because its
>> not in
>> my jurisdiction
>> -notified the programmers and sent slow queries
>> -indexes used
>> -tryed to make some status with mk-query-filter
>> -Explain
>>
>> Generally this Question may not be useful but I only wanted to know
>> replication connections with
>> these variables that i modified and gave myself additional work to
>> fix replication.
>>
>> * Conclusion:
>>
>> *Replication does not like* high buffer* values and high
>> max_allowed_packet on master. Our max_allowed_packet
>> stayed as default at 1M which is ok and works fine (this variable
>> was not changed in my tunning).
>> max_allowed_packet=1M (because of LOAD DATA command), high values
>> broke replication with same error 1236.
>> MySQL phenomenon errors once more.
>>
>> Thank you.
>>
>> Sorry for a long long description.
>>
>>
>
--
Andrej Pintar
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