On Wednesday, 19 May 2010 22:02:57 DT Piotr Wadas wrote: > Hello, > > Does it make any sens to enable indexing of any attribute on read-only > slave syncrepl replica?
Whether or not indexes make sense is not dependant on whether the LDAP service is a provider or consumer or not, but dependent on what searches the LDAP service serves. For example, if a provider only provides writes and changes to consumers, but no searches from clients, it only makes sense to index attributes required for replication. If a consumer is run purely for making offline backups of the master (e.g. by slapcat), and serves no searches, it may also make sense to index only replication attributes. > I mean, isn't it just waste of resources, or, > actually, is not a waste a resources at all, since replica is read-only > and does not write anything anyway? While a replica doesn't accept any changes from clients, it will write just as much as it's provider does on the same dataset, or it isn't doing a good job of replicating. Typically, one normally configures the environment to direct read operations to slaves, so typically they have a higher read/write ratio, and it makes sense to have more indexes on slaves (the additional write IO for maintaining indexes is justified). Regards, Buchan
