Common SCOM Server myths: Tweaking Resource PoolManager Registry Keys

Tweaking Resource PoolManager Registry Keys is always helpful or in opposite it’s not a valid setting anymore

FALSE!

Why helpful?

Starting with SCOM 2012 Release candidate (RC) there was a quick fix to add PoolManager Registry Keys for tuning the pool member availability detection. This makes sense because in a pool with running too much workflows and with a small default value for the PoolLeaseRequestPeriodSeconds or PoolNetworkLatencySeconds this could produce false negative by rebalancing members of the pool. You will get alerts like “The All Management Servers Pool has not reported availability” or other 1500* events complaining about pool member becoming unavailable or available again. What happens under the hood is that workflows were rebalanced between pool members which is in general a bad behavior in your management group. In the KB Article (which is not present anymore) we recommended new values below the key HKLM\SYSTEM\CurrentControlSet\services\HealthService\Parameters\PoolManager\

with REG_DWORD settings (decimal) of
PoolLeaseRequestPeriodSeconds = 600
PoolNetworkLatencySeconds = 120

The PoolLeaseRequestPeriod Seconds defines how often a pool member sends and waits for lease request.

The PoolNetworkLatencySeconds adjusts the delivery latency for pooling messages.

Why not always helpful?

Kevin and Dirk blogged about it. The resource pools work quite well in SCOM 2012 SP1/R2 on their own and typically the settings just needed for large environments with high workloads and with very special conditions. And very important this keys (if used) should be created on all Management Servers with the same value and with a good understanding of the impact they will have on your environment.

Why valid?

Even the corresponding KB is pulled and we have fixed several issues in SCOM 2012 SP1 and SCOM 2012 R2, these keys could be still used for special conditions. As mentioned above, the registry-keys are not in general bad, but should be used with care. When you use this keys then these keys should be present (again!!!) on all MS. In short: I never had a situation where we need this on customer side in a SCOM 2012 R2 (or SP1) environment, but several situations where upgraded environments have this keys still present (and with negative effects if the customer forgets to adjust this for new installed Management Servers: Resulting in a bad Ping Pong between Resource Pool Members).

Comments

• Anonymous
  January 26, 2017
  HiIf you get pool manager alert on gateway servers, should I change these values on all servers in the pool, or on all management servers, regardless of them being in this particular pool?
  • Anonymous
    January 27, 2017
    Please do it on all Management Servers