How does automatic JVM memory negotiation work for database agents (4376153)

How does automatic JVM memory negotiation work for database agents

How does automatic JVM memory negotiation work for database agents?

When adding a new database agent or when adding SQL PI to an existing database agent, a popup titled "Insufficient Resources" appears with the message "Agent Manager AGENT_NAME_NAME has insufficient memory allocation. Memory allocation needs to be increased by at least 192.0 MB according to the Deployment Guide." This is followed by two radio button options

• Proceed with the installation while the wizard will automatically attempt to increase the Agent Manager memory allocation once the DB agent is created. The Agent Manager will restart automatically.
•  Proceed with the installation and increase resources later.

This popup refers to the memory allocation sizing for the Java Virtual Machine (JVM) heap, and not the physical memory on the server. Each SQL Server agent requires minimum memory (Xms) of 20MB and maximum memory (Xmx) of 80MB. Since not all of the database agents are configured with PI, there is no reason to define a minimum memory of 80MB in advance, the JVM will claim the additional memory allocation it if requires it.

A memory allocation is pre-defined for five agents. Beginning with the sixth agent creation, each new agent will request an additional memory allocation of 80MB. The FglAM will check if the additional memory is more than 10% of the total allocation memory, and it if is, will try to allocate the new requested memory.
NOTE: The additional memory requires a FglAM restart, the restart will be done after a minimum of one minute quiet period (where no other resource negotiation requests wills come).

When there are not enough resources for the FglAM to allocated, the resource allocation will fail, but the agent creation will succeed as it is an independent operation.

The agent will continue to check the FglAM's available memory on each agent creation during the Wizard flow.
 

SUMMARY

The dynamic FglAM resource negotiation support works as follows:

• If the installer detects that there is not enough memory on the monitoring FglAM for the new agent:

  • an inefficient resources error message will be popped-up which includes the required memory amount.

  • The user will have the option to choose automatic memory settings or to defer an automatic increase of the JVM allocation in the background later.

• At the end of the installation, after the new agent creation, JVM memory allocation will be accumulated with the total requests from the previous cycle.

RESOLUTION 1
Select the top radio button and allow the JVM memory allocation to be assigned automatically by Foglight in the background. Then click the OK button


RESOLUTION 2
Select the bottom radio button to defer adding the additional resources to a later time, this choice is offered because the memory allocation process restarts the FglAM in the background. This additional memory allocation can be done manually by adding the baseline.jvmargs.config file on the FglAM. Refer to Knowledgebase article 4308627 for more details.