We are not able to see the data for the past days for one of the agent. We do have data for rest of the agents in the same collector for those days.
When I check for the metrics for the past 3 days, I can see something like below screenshot. I am not sure how we lost the data. Yesterday I had to restart this collector after changing the value as lax.nl.java.option.additional=-Xms4g -Xmx4g in "Introscope_Enterprise_Manager.lax" file and after that I can see this data loss.
Any guesses why it happened?. How should I retrieve the data for this agent?
If the agent log shows no ERRORs for the connection to the Enterprise Manager (MOM) have you checked for a metric clamping problem on your Agent/Collectors?
The APM Status Console (The APM Status Console - CA Application Performance Management - 10.1 - CA Technologies Documentation ) or these metrics should tell you
*SuperDomain*|Custom Metric Host (Virtual)|Custom Metric Process (Virtual)|Custom Metric Agent (Virtual)(<collector_name>)(*SuperDomain*)|Agents|<agent name>: IsClamped
*SuperDomain*|Custom Metric Host (Virtual)|Custom Metric Process (Virtual)|Custom Metric Agent (Virtual)(<collector_name>)(*SuperDomain*)|Enterprise Manager|Connections|EM Live Metric Clamped
*SuperDomain*|Custom Metric Host (Virtual)|Custom Metric Process (Virtual)|Custom Metric Agent (Virtual)(<collector_name>)(*SuperDomain*)|Enterprise Manager|Connections|EM Historical Metric Clamped
Hope it helps
There is no metric clamping on the agents/collectors. On that day after a restart these agents were connected to a new collector and added under a new domain name. It was under SuperDomain in previous collector. Do you think this is one of the reason for loss of historical data for these agents?
That is exactly the reason for the 'loss' of data. The full name of any agent takes into consideration the domain name, so the historical data of the agent under SuperDomain is not the same as under a custom domain.
There is no way to resolve this in the way that the product is designed, the data from the two agents will be considered distinct, at a data level, they are considered two different agents.
All of the data is technically still there.
If the agent was mapped back to Super Domain, you would see the historical data again for the agent, but of course it would be mapped back to the SuperDomain, and you would have a gap of a few days' data while the agent was mapped to a different domain.