KVM: probable problem with storage stats when storage is put on maintenance #5775
Description
ISSUE TYPE
- Bug Report
COMPONENT NAME
Primary storage - excluding Ceph/non managed NFS
CLOUDSTACK VERSION
main and older versions
CONFIGURATION
OS / ENVIRONMENT
OS - CentOS7
hypervisor - KVM
mgmt/agent version - 4.16.0.0
SUMMARY
When you put the primary storage on Maintenance mode and restart the agent, the storage will be removed from the storage adaptor's map. This causes NullPointerException when collecting the storage statistics. The problem is probably for all storage pools which don't use LibvirtStorageAdaptor - e.g. Linstor, StorPool maybe, and SolidFire.
This does not affect Ceph and non managed NFS, also and PowerFlex (PowerFlex does not call the agents to get the storage statistics)
STEPS TO REPRODUCE
set storage.stats.interval on short interval
enable storage maintenance mode
restart the agents
EXPECTED RESULTS
collect or don't the storage stats on pools on Maintenance mode
ACTUAL RESULTS
2021-12-15 08:31:03,586 DEBUG [cloud.agent.Agent] (agentRequest-Handler-3:null) (logid:552801e3) Processing command: com.cloud.agent.api.GetStorageStatsCommand
2021-12-15 08:31:03,586 WARN [cloud.agent.Agent] (agentRequest-Handler-3:null) (logid:552801e3) Caught:
java.lang.NullPointerException
at com.cloud.hypervisor.kvm.resource.wrapper.LibvirtGetStorageStatsCommandWrapper.execute(LibvirtGetStorageStatsCommandWrapper.java:40)
at com.cloud.hypervisor.kvm.resource.wrapper.LibvirtGetStorageStatsCommandWrapper.execute(LibvirtGetStorageStatsCommandWrapper.java:32)
at com.cloud.hypervisor.kvm.resource.wrapper.LibvirtRequestWrapper.execute(LibvirtRequestWrapper.java:78)
at com.cloud.hypervisor.kvm.resource.LibvirtComputingResource.executeRequest(LibvirtComputingResource.java:1768)
at com.cloud.agent.Agent.processRequest(Agent.java:661)
at com.cloud.agent.Agent$AgentRequestHandler.doTask(Agent.java:1079)
at com.cloud.utils.nio.Task.call(Task.java:83)
at com.cloud.utils.nio.Task.call(Task.java:29)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
2021-12-15 08:31:03,588 DEBUG [cloud.agent.Agent] (agentRequest-Handler-3:null) (logid:552801e3) Seq 60-4602115869219225621: { Ans: , MgmtId: 2199191159196, via: 60, Ver: v1, Flags: 10, [{"com.cloud.agent.api.Answer":{"result":"false","details":"java.lang.NullPointerException