Merge pull request #2262 from HubSpot/fix-decommissioned-task-npe

Fix npe for tasks with null hostnames from decommissioned host resources

Author: WH77

SingularityService/src/main/java/com/hubspot/singularity/mesos/SingularityAgentAndRackManager.java

@@ -800,18 +800,7 @@ public void checkDecommissionedAgentsFromMaster(
 
     for (MesosMasterAgentObject agentJsonObject : state.getAgents()) {
       String agentId = agentJsonObject.getId();
-      if (agentsById.containsKey(agentId)) {
-        SingularityAgent agent = agentsById.get(agentId);
-        if (agent != null) {
-          LOG.info(
-            "Found resources ({}) for decommissioned agent {}",
-            agentJsonObject.getResources(),
-            agent
-          );
-          agentManager.saveObject(agent.withResources(agentJsonObject.getResources()));
-        }
-        agentsById.remove(agentId);
-      }
+      agentsById.remove(agentId);
     }
 
     for (SingularityAgent leftOverAgent : agentsById.values()) {

SingularityService/src/main/java/com/hubspot/singularity/mesos/SingularityStartup.java

@@ -108,8 +108,8 @@ public void startup(MasterInfo masterInfo) {
 
     MesosMasterStateObject state = mesosClient.getMasterState(uri);
 
-    agentAndRackManager.loadAgentsAndRacksFromMaster(state, true);
     agentAndRackManager.checkDecommissionedAgentsFromMaster(state, true);
+    agentAndRackManager.loadAgentsAndRacksFromMaster(state, true);
 
     ExecutorService startupExecutor = Executors.newFixedThreadPool(
       configuration.getSchedulerStartupConcurrency(),