Is max_allowed_packet = 1M on both Slave and Master?
server_id is different?
Master did not crash?
Using MyISAM or InnoDB??
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.
>
>
--
Rick James - MySQL Geek
