[ https://issues.apache.org/jira/browse/YARN-9371?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Bilwa S T reassigned YARN-9371: ------------------------------- Assignee: (was: Bilwa S T) > Better logging for initialization of cgroups in CGroupsHandlerImpl > ------------------------------------------------------------------ > > Key: YARN-9371 > URL: https://issues.apache.org/jira/browse/YARN-9371 > Project: Hadoop YARN > Issue Type: Improvement > Reporter: Szilard Nemeth > Priority: Major > > We already have YARN-9098 that dealt with (not yet merged, though) code > duplication in cgroups setup code. > However, there's still room for improvement in the area of cgroups > initialization, especially in CGroupsHandlerImpl. > 1. > org.apache.hadoop.yarn.server.nodemanager.containermanager.linux.resources.CGroupsHandlerImpl#initializeControllerPaths: > There's a decision in this method: Either cgroups are parsed from the > configured mount path or from the mounted cgroups descriptor file > (/proc/mounts). This decisions needs to be logged, along with some details, > e.g. cgroups mount path. > 2. In ResourceHandlerModule#parseConfiguredCGroupPath: Every candidate file > could be logged to debug. Moreover, the returned pathSubsystemMappings could > be also logged to info. > 3. In CGroupsHandlerImpl#parseMtab: This method iterates over lines of the > mtab file, tries to match the line and parses data of cgroups. > We need to better have logs for: > - If the line does not match: Print the line (I think debug level is fine for > that) > - We could log the entire result map to info log. > 4. In CGroupsHandlerImpl#initializeControllerPaths, > initializeControllerPathsFromMtab is called. This method returns mapping of > cgroups controllers (cpu, memory, devices, etc.) to file system paths. This > is an important piece of information for troubleshooting, so the map needs to > be logged to info. > 5. In CGroupsHandlerImpl#initializeCGroupController: There's a condition for > enableCGroupMount, I think it's worth to log if we are dealing with > YARN-driven cgroups mount or pre-mounted controllers. > 6. In CGroupsHandlerImpl#mountCGroupController: > - existingMountPath needs to be logged for better troubleshooting > - Other debug logs could also be added, this is up to the owner of this jira. > 7. In CGroupsHandlerImpl#initializePreMountedCGroupController: > - controllerPath needs to be logged for better troubleshooting. > - Other debug logs could also be added, this is up to the owner of this jira. > > A side-note: Implementing this Jira could be way easier after YARN-9098 is > merged as that Jira eliminated lots of code duplication and made the > initialization of cgroups more clear and concise. > -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org