ZooKeeper
  1. ZooKeeper
  2. ZOOKEEPER-856

Connection imbalance leads to overloaded ZK instances

    Details

    • Type: Bug Bug
    • Status: Open
    • Priority: Major Major
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: 3.5.0
    • Component/s: None
    • Labels:
      None

      Description

      We've experienced a number of issues lately where "ruok" requests would take upwards of 10 seconds to return, and ZooKeeper instances were extremely sluggish. The sluggish instance requires a restart to make it responsive again.

      I believe the issue is connections are very imbalanced, leading to certain instances having many thousands of connections, while other instances are largely idle.

      A potential solution is periodically disconnecting/reconnecting to balance connections over time; this seems fine because sessions should not be affected, and therefore ephemaral nodes and watches should not be affected.

        Activity

        Mahadev konar made changes -
        Fix Version/s 3.5.0 [ 12316644 ]
        Fix Version/s 3.4.0 [ 12314469 ]
        Mahadev konar made changes -
        Assignee Mahadev konar [ mahadev ]
        Mahadev konar made changes -
        Fix Version/s 3.4.0 [ 12314469 ]
        Travis Crawford made changes -
        Field Original Value New Value
        Attachment zk_open_file_descriptor_count_total.gif [ 12453157 ]
        Attachment zk_open_file_descriptor_count_members.gif [ 12453158 ]
        Travis Crawford created issue -

          People

          • Assignee:
            Mahadev konar
            Reporter:
            Travis Crawford
          • Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

            Dates

            • Created:
              Updated:

              Development