Epic Link query causes timeouts

Problem Definition

While Jira 8 has made great strides in performance, there remain a few operations that are regularly 5+ seconds. I'm singling out Epic Link query performance because I'm noticing this is one of our top-ranked common operations. This can cause delays and block stories from being created when the Epic Link is a required field on the create screen.

Steps to reproduce

You can experience this when you:

1. Edit an Issue
2. fill out the `E_pic Link_` value
   • Jira will generate the XHR request -/rest/greenhopper/1.0/epics

Suggested Solution

Epic data loads within 3 seconds.

Notes

• Data from the access logs:

  5.719 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582316504312
  5.830 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582317208392
  5.832 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=false&_=1582305640419
  5.861 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582318961711
  5.916 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582305972667
  5.948 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582297025081
  5.963 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=false&_=1582311915016
  6.012 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582314026469
  6.161 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true&_=1582314877488
  6.313 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true?searchQuery=&projectKey=XXX&maxResults=10&hideDone=true
  6.440 /rest/greenhopper/1.0/epics?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true?searchQuery=&projectKey=XXX&maxResults=100&hideDone=true
  

• Here are our Epic Statistics. Total Epics: 28K
  • issuetype=Epic and statusCategory = Done : count: 14k
  • issuetype=Epic and statusCategory != Done : count: 14k

Some sample thread dumps in case they are helpful

• Snippet1

  "http-nio-8082-exec-107" #2634 daemon prio=5 os_prio=0 tid=0x00007f5dbca36800 nid=0x54fe runnable [0x00007f5d5cc0b000]
     java.lang.Thread.State: RUNNABLE
  	at java.util.ArrayList.indexOf(ArrayList.java:321)
  	at java.util.ArrayList.contains(ArrayList.java:304)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback.lambda$orderEpicByName$5(EpicLabelAndKeyMatchingCallback.java:252)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback$$Lambda$8850/1016207412.apply(Unknown Source)
  	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
  	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
  	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482)
  	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472)
  	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
  	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
  	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:566)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback.orderEpicByName(EpicLabelAndKeyMatchingCallback.java:253)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback.getIssues(EpicLabelAndKeyMatchingCallback.java:233)
  	at com.atlassian.greenhopper.service.issuelink.EpicPickerServiceImpl.listEpicNames(EpicPickerServiceImpl.java:69)
  	at com.atlassian.greenhopper.web.rapid.issue.issuelink.EpicResource$4.call(EpicResource.java:225)
  	at com.atlassian.greenhopper.web.rapid.issue.issuelink.EpicResource$4.call(EpicResource.java:218)
  	at com.atlassian.greenhopper.web.util.RestCall.response(RestCall.java:42)
  	at com.atlassian.greenhopper.web.AbstractResource.createResponse(AbstractResource.java:111)
  	at com.atlassian.greenhopper.web.AbstractResource.responseWithoutAccessCheck(AbstractResource.java:105)
  ..
  

• Snippet2

  "http-nio-8082-exec-107" #2634 daemon prio=5 os_prio=0 tid=0x00007f5dbca36800 nid=0x54fe runnable [0x00007f5d5cc0b000]
     java.lang.Thread.State: RUNNABLE
  	at java.util.ArrayList.indexOf(ArrayList.java:321)
  	at java.util.ArrayList.contains(ArrayList.java:304)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback.lambda$orderEpicByName$5(EpicLabelAndKeyMatchingCallback.java:252)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback$$Lambda$8850/1016207412.apply(Unknown Source)
  	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
  	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
  	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482)
  	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472)
  	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
  	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
  	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:566)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback.orderEpicByName(EpicLabelAndKeyMatchingCallback.java:253)
  	at com.atlassian.greenhopper.service.issue.callback.EpicLabelAndKeyMatchingCallback.getIssues(EpicLabelAndKeyMatchingCallback.java:233)
  	at com.atlassian.greenhopper.service.issuelink.EpicPickerServiceImpl.listEpicNames(EpicPickerServiceImpl.java:69)
  	at com.atlassian.greenhopper.web.rapid.issue.issuelink.EpicResource$4.call(EpicResource.java:225)
  	at com.atlassian.greenhopper.web.rapid.issue.issuelink.EpicResource$4.call(EpicResource.java:218)
  	at com.atlassian.greenhopper.web.util.RestCall.response(RestCall.java:42)
  	at com.atlassian.greenhopper.web.AbstractResource.createResponse(AbstractResource.java:111)
  	at com.atlassian.greenhopper.web.AbstractResource.responseWithoutAccessCheck(AbstractResource.java:105)
  ...
  

Code samples

• com.atlassian.greenhopper.web.rapid.issue.issuelink.EpicResource#listEpics

  /**
   * Resource for changing epic-issue links.
   */
  @Path("epics")
  @AnonymousAllowed
  @Consumes({MediaType.APPLICATION_JSON})
  @Produces({MediaType.APPLICATION_JSON})
  
  ...
  public Response listEpics(@QueryParam("searchQuery") final String searchQuery, @QueryParam("maxResults") final int maxResults, @QueryParam("projectKey") final String projectKeys, @QueryParam("hideDone") final boolean hideDone, @QueryParam("query") final String query, @QueryParam("filterEpicsByGivenProjects") final boolean filterEpicByGivenProjects)
   ...
  
                  List<EpicNamesResult> epicNamesResults = check(epicPickerService.listEpicNames(user, searchTerm, maxResults, projectKeys, hideDone, filterEpicByGivenProjects));
  
                  FindEpicNamesResponse response = new FindEpicNamesResponse();
                  for (EpicNamesResult epicResult : epicNamesResults)
                  {
                      EpicNameListModel list = new EpicNameListModel(epicResult.getListDescriptor());
                      for (EpicModel epicName : epicResult.getNames())
                      {
                          String key = epicName.getEpicKey();
                          String label = epicName.getEpicName();
                          label = epicLabelProvider.getEpicLabel(key, label);
                          list.epicNames.add(new EpicNameModel(key, label, epicName.isDone()));
                      }
                      response.epicLists.add(list);
                      response.total = epicResult.getTotal();
                  }
  
                  return createOkResponse(response);
              }
          });
      }
  

  Workaround:

  There is no workaround currently for this issue