SPDI-54500. Backport Fix metrics Worker.ActiveClients counter error A…

…lluxio#14088

Fix metrics Worker.ActiveClients counter error

Fix metrics Worker.ActiveClients counter error

When executing end-to-end test: allxuio runTest --readType NO_CACHE
--writeType THROUGH. the counter metric Worker.ActiveClients.xxx will
change to 2 instead of 0.

No

pr-link: Alluxio#14088
change-id: cid-9bfb67ba59896c03827a0bc8c84901f931a41ba6

core/server/worker/src/main/java/alluxio/worker/block/DefaultBlockWorker.java

@@ -651,6 +651,13 @@ public void closeUfsBlock(long sessionId, long blockId)
           // the sessionId.
           LOG.debug("Invalid worker state while committing block.", e);
         }
+      } else {
+        // When getTempBlockMeta() return null, such as a block readType NO_CACHE writeType THROUGH.
+        // Counter will not be decrement in the commitblock().
+        // So we should decrement counter here.
+        if (mUnderFileSystemBlockStore.isNoCache(sessionId, blockId)) {
+          Metrics.WORKER_ACTIVE_CLIENTS.dec();
+        }
       }
     } finally {
       mUnderFileSystemBlockStore.releaseAccess(sessionId, blockId);

core/server/worker/src/main/java/alluxio/worker/block/UnderFileSystemBlockStore.java

@@ -246,6 +246,18 @@ public BlockReader getBlockReader(final long sessionId, long blockId, long offse
     return reader;
   }
 
+  /**
+   * @param sessionId the session ID
+   * @param blockId the block ID
+   * @return true if mNoCache is set
+   */
+  public boolean isNoCache(long sessionId, long blockId) {
+    Key key = new Key(sessionId, blockId);
+    BlockInfo blockInfo = mBlocks.get(key);
+    UnderFileSystemBlockMeta mMeta = blockInfo.getMeta();
+    return mMeta.isNoCache();
+  }
+
   /**
    * Gets the {@link UnderFileSystemBlockMeta} for a session ID and block ID pair.
    *