Running a replica-set with 1 primary and 2 secondaries, I wonder why the READs are also done on the primary. Shouldn't the primary mainly do the WRITEs and the secondary can share the READ-load?!
I am using the PHP driver for the mongodb and sending the details for replica set. The PHP is running from the secondaries and in the script the intitial connection goes to the secondary itself which is localhost there.
The php documentation says, that the driver will find the primary and secondaries on its own as soon as it connects to any member of the replica-set, no matter if primary or secondary.
After checking the load and logs, I found out that currently my poor primary has to deal with all the READs and the slaves are bored.