[ZOOKEEPER-1652] zookeeper java client does a reverse dns lookup when connecting

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Duplicate
• Affects Version/s: 3.4.5
• Component/s: java client
• Assignee: Sean Bridges
• Reporter: Sean Bridges
• Created: 26/Feb/13 18:45
• Updated: 26/Oct/16 14:25
• Resolved: 05/Nov/13 02:34

Description

When connecting to zookeeper, the client does a reverse dns lookup on the hostname. In our environment, the reverse dns lookup takes 5 seconds to fail, causing zookeeper clients to connect slowly.

The reverse dns lookup occurs in ClientCnx in the calls to adr.getHostName()

            setName(getName().replaceAll("\\(.*\\)",
                    "(" + addr.getHostName() + ":" + addr.getPort() + ")"));
            try {
                zooKeeperSaslClient = new ZooKeeperSaslClient("zookeeper/"+addr.getHostName());
            } catch (LoginException e) {

Issue Links

• duplicates: ZOOKEEPER-1666 Avoid Reverse DNS lookup if the hostname in connection string is literal IP address.
• is blocked by: ZOOKEEPER-1666 Avoid Reverse DNS lookup if the hostname in connection string is literal IP address.
• is cloned by: ZOOKEEPER-1661 Random (?) 5s delay when establishing connection