Changing the Limit for Concurrent Mirror Operations Using the CLI
The system allows a maximum of 50 concurrent mirroring operations by default. Mirroring
operations include both mirroring and promoting from read-only mirrors to
read-write standard volumes. The system parameter that controls this limit is
mapr.mirror.concurrent.ops
. This system parameter is set on
the destination cluster.
For large-scale mirror
operations involving many volumes, a script automates the process.
For example, if a script queues 100 volumes for mirroring
operations, and the mapr.mirror.concurrent.ops
limit is set to 50, the mirroring
operations start on the first 50 volumes in the queue. As soon as
one volume completes, another volume is processed from the queue
until all 100 are completed. Since volumes are processed from the
queue in first-in first-out (FIFO) order, the script should specify
the most critical volumes first.
If you want to process more volumes at a time, you can raise the limit of the
mapr.mirror.concurrent.ops
parameter. To tune this
parameter for maximum efficiency, consider the number of containers per volume. A
higher number of containers per volume requires a lower limit than a lower number
of containers per volume. To raise the limit to 500 for example, run the following
command on the destination cluster:
maprcli config save -values {"mapr.mirror.concurrent.ops":"500"}