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From:Gary W. Smith Date:March 1 2007 11:46pm
Subject:RE: Replication performance questions
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I could be wrong BUT...

> 1) Does increasing the number of replication slaves increase query
> latency on the master?  We're considering tiering the replication if
> it might help - replicate the master to two slaves, each of which
> replicates to ten clients.

The slaves should only be pulling from the log file, not querying the
master data directly.  But yes, I guess I could cause an additional load
on the server if there are many many slaves.  But with < 10,000 updates
a day (that is 8 per minute, this shouldn't be much of a load at all.
 
> 2) Is there a chance that the insert latency is coming from the fact
> that the table is growing so long?  At a certain point, even with
> indexes, I imagine that the engine is going to have to do some linear
> searching.

Well, back to answer 1.  Replication is about log's, not querying the
data.  

You mentioned updates, but what about querying the data.  Do you run a
lot of queries against the data on the master server?  We have a
database with 50M rows in it and we have a complicated replication
strategy for the reader just so we can take 99% of the load off the
master.  We have a slave'd database just to run reports from (actually
we have a load balanced cluster of them).  The master received inserts
about 20 records/s

Also, what type of database are you using?  INNODB?  MyISAM?  If you are
running MyISAM then things can get slow on updates.

Thread
Replication performance questionsRoss Vandegrift2 Mar
  • RE: Replication performance questionsGary W. Smith2 Mar
    • RE: Replication performance questionsGary W. Smith2 Mar
    • Re: Replication performance questionsRoss Vandegrift2 Mar
      • RE: Replication performance questionsGary W. Smith2 Mar
        • Re: Replication performance questionsRoss Vandegrift2 Mar
          • RE: Replication performance questionsGary W. Smith2 Mar
            • Re: Replication performance questionsRoss Vandegrift6 Mar
              • Re: Replication performance questionsAtle Veka9 Mar