Setting the ping-timeout Database Option

Engine-level failure detection

To enable failure detection, set the ping-timeout n database option, where n is the timeout interval in seconds. NuoDB recommends an interval timeout of 60 seconds or greater. For more information on ping-timeout, see Database Options.

With failure detection enabled using ping-timeout, when network communication with a process times out or the network connection is shut down unexpectedly, the process is evicted from the database by its peers. See Setting Up Failure Detection.

Broker-level failure detection

The heartbeatPeerTimeout property, in the NUODB_HOME/etc/ file, is set to an interval of 60 seconds or greater. Brokers ping their connected peer(s) periodically. A peer sends a warning to its agent log if it does not receive acknowledgement of its initial ping after 10 seconds and then continually after that. See Host Properties (

The default behavior, heartbeatPeerTimeout=0, is that a peer waits for a ping acknowledgement forever and does not disconnect a non-responsive peer. For a peer to automatically disconnect a non-responsive peer, set heartbeatPeerTimeout to a value greater than the setting of the RaftMaxElectionTimeout property. The default setting for that property is 8300 milliseconds. NuoDB recommends a minimum setting of 20 seconds for the heartbeatPeerTimeout property.

When heartbeatPeerTimeout is set to a value greater than 0 and that length of time elapses before this peer receives a ping acknowledgement from another peer then this peer closes the session and disconnects with the non-responsive peer.

A broker reports disconnected peers to all reachable brokers in the domain. Disconnected peers periodically try to reconnect. A broker tries to peer back into the domain according to the durable domain configuration. A broker tries to reconnect to another broker in the domain.

On this peer’s host, execution of the NuoDB Manager show domain hosts command indicates that the non-responsive peer and any database processes (TEs, SMs, SSMs) associated with the non-responsive peer are UNREACHABLE. The status of a peer as unreachable does not change the durable domain configuration. See NuoDB Manager Show Domain