Maximum possible slave database delay (sec.) - after this time data will be automatically disabled to reduce risk of data unsynchronization.
Slave database delay is possible with a significant number of main (master) database updates, insufficiently quick connection between database master and slave, insufficient database slave performance.
Note: database delay time is displayed in the table at the
Database replication is a process of creating and supporting its copy up to date...
Group is an entity created only for purposes of convenience. Groups are used for merging "nodes" within a geo cluster. This allows to allocate the following custom hardware in different geographically-located data centers: database servers, Memcached-servers, Web server.
Groups are created at the page Settings > Web Cluster > Server Groups. You need to just assign a name to a created group.
Important! Each web server in a single group inside the file dbconn.php must have a defined variable BX_CLUSTER_GROUP with value matching to a group ID. Foe example: define("BX_CLUSTER_GROUP", 1).
Name of a second group can be "Group No.2", but the variable BX_CLUSTER_GROUP must have an actual (autoincremental) identifier of this group that can be viewed at the page with list of server groups (Settings > Web Cluster > Server Groups).
The file dbconn.php should't be synchronized between groups.