When does a hub become necessary?
Hi,
I've got a DS5.2 environment that currently has 2 masters (multi-master), 2 hubs and 10 consumers.
I'm wondering whether the inclusion of hubs actually provides us any benefit, or if it would actually be better to remove them and replicate to the consumers directly from our suppliers?
Is there a 'rule of thumb' about the size of environment when using a hub will provide performance/stability benefits?
Thanks,
Mark.
[463 byte] By [
oztricha] at [2007-11-27 8:31:55]
# 1
Hubs do remove some of the load from the Masters, as each Master will have only 3 replication agreements and not 11 (one to the other master, one for each consumer).
With 5.2, I think we estimated that each replication agreement would use about 1/4 of a CPU if the server was under heavy load.
Hubs can also be promoted to Masters if one of the Master is taken down, and thus provide a fast and low cost recovery capability.
Hubs could be optimized to contain the minimal indexes required (system ones). But this can limit their ability to be promoted to Master.
And in general, I would not consider hubs if there are less than 4 consumers. And would recommend them starting with 8 consumers. Of course, this depends on the kind of machines, the work load and the CPU load available on the machines.
Regards,
Ludovic.
