281221 - Add section explaining configuration tips for large Bugzilla installations

Status: RESOLVED INCOMPLETE

(Bugzilla :: Documentation, enhancement)

Description

[Joel Peshkin]

Sites that have monster databases and large traffic loads often require their
own special techniques.

For example, to upgrade my site (with 12GB worth of databases) from Mysql 3.23
to Mysql 4.1 and from 2.17 to 2.19, there are several tricks required even to do
the preliminary dry-run upgrades.  The technique that seems to work the best is
to mysqldump (4.1) the replica of the live site and pipe that to mysql to load
the master of the new site.  Standard mysqldump options will not work in this
case.  
1) mysqldump must be told not to defer indexing until each table is loaded (or
else the transfer will time out as it pauses while the attachments index is
built all-at-once)
2) The new site's master server should suspend replication while it is being
loaded (to save time, this will eventually become downtime during the final
transition).  After the new master is loaded, the slave should reload from the
master.
3) Already in the docs, but worth mentioning here, the default max table size of
the attachments table should be changed when the tables are created.

I'd also suggest that we put a note in about backup strategies.  Backing up the
replica really helps, though it is probably good advice to lock the replica
during backups.

Comment 1

[Gervase Markham [:gerv]]

We could certainly have this, but we'd need the admin of a large installation to write it. In absence of one, marking INCOMPLETE.

Gerv