[HADOOP-7456] Connection with RemoteException is not removed from cached HashTable and cause memory leak

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 0.20.2
• Component/s: fs
• Assignee: Unassigned
• Reporter: Angelo K. Huang
• Created: 09/Jul/11 01:08
• Updated: 12/Jul/11 22:52
• Resolved: 12/Jul/11 02:59

Description

In a long running system like Oozie, we use hadoop client APIs, such as FileSystem.exists(), to check files exist on hdfs or not to kick off a user job. But in a production environment, user sometimes gives wrong or invalid format of file/directory paths. In that case, after server was up for couple days, we found around 80% of memory were taken away by hadoop ipc client connections. In one of the connections, there was a hashtable contains 200k entries. We cross-checked Hadoop code and found out that in org.apache.hadoop.ipc.Client.receiveResponse(), if state if fatal, the call object does not remove from the hashtable (calls) and keeps in the memory until system throws OutOfMemory error or crash. The code in question is here :

• org.apache.hadoop.ipc.Client.receiveResponse()
  } else if (state == Status.FATAL.state) { // Close the connection markClosed(new RemoteException(WritableUtils.readString(in), WritableUtils.readString(in))); }

Issue Links

• duplicates: HADOOP-6833 IPC leaks call parameters when exceptions thrown