Limiting concurrent performance extractions

This topic only applies to Resource Manager 4.x systems. Skip this topic if you are running a Resource Manager 5.x or 6.x system.

Since multiple logical collectors can be installed on a single host, there will be multiple zenperfetl daemons running on the same host. Under normal conditions, these daemons will begin extraction nearly simultaneously, which can saturate disk I/O for a period of time. To manage this behavior, Analytics tracks the hosts where each of its performance extractors are running. There is a concurrent_extractions_limit column in the meta_perf_extractor_limits table. By default, there is no limit. If you have an environment where there are many logical collectors installed on a single host, you may want to change the value of concurrent_extractions_limit to limit the number of concurrent performance extractions that can take place at the same time on the host.

To change the value, you must edit the meta_perf_extractor_limits table directly:

1. Log in to the Analytics data warehouse database as the root user or a user with administrative permissions.
mysql -u root reporting
2. Enter the following to set the concurrent_extractions_limit to a value of 4. The actual value you will want to use depends on your disk I/O.
update meta_perf_extractor_limits set setting_value = '4' where setting_name = 'concurrent_extractions_limit';