Package io.hekate.cluster.split

Class HostReachabilityDetector

java.lang.Object

io.hekate.cluster.split.HostReachabilityDetector

All Implemented Interfaces:

SplitBrainDetector, ConfigReportSupport

public class HostReachabilityDetector
extends Object
implements SplitBrainDetector, ConfigReportSupport

Host reachability-based detector.

This implementation of SplitBrainDetector utilizes InetAddress.isReachable(int) method to check if some pre-configured host address is reachable. Assumption is that if local node can reach that host then it is not cut off the network and can communicate with other nodes.

Note that it is possible to combine multiple detectors with the help of SplitBrainDetectorGroup.

See Also:

ClusterServiceFactory.setSplitBrainDetector(SplitBrainDetector)

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_TIMEOUT	Default value (=3000) in milliseconds for the timeout parameter of HostReachabilityDetector(String, int).

Constructor Summary

Constructors

Constructor	Description
HostReachabilityDetector(String host)	Constructs new instance with the default timeout value (=3000).
HostReachabilityDetector(String host, int timeout)	Constructs new instance.

Method Summary

Modifier and Type	Method	Description
String	host()	Host to check.
boolean	isValid(ClusterNode localNode)	Performs a split-brain check and returns true if local node can reach other members of the cluster.
void	report(ConfigReporter report)	Report configuration.
int	timeout()	Check timeout in milliseconds.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_TIMEOUT

public static final int DEFAULT_TIMEOUT

Default value (=3000) in milliseconds for the timeout parameter of HostReachabilityDetector(String, int).

See Also:

Constant Field Values

Constructor Detail

HostReachabilityDetector

public HostReachabilityDetector(String host)

Constructs new instance with the default timeout value (=3000).

Parameters:

host - Host to be checked for reachability.

HostReachabilityDetector

public HostReachabilityDetector(String host,
                                int timeout)

Constructs new instance.

Parameters:

host - Host to be checked for reachability.

timeout - Timeout in milliseconds for host reachability checking (see InetAddress.isReachable(int)).

Method Detail

report

public void report(ConfigReporter report)

Description copied from interface: ConfigReportSupport

Report configuration.

Specified by:

report in interface ConfigReportSupport

Parameters:

report - Reporter.

host

public String host()

Host to check.

Returns:

Host to check.

timeout

public int timeout()

Check timeout in milliseconds.

Returns:

Timeout in milliseconds.

isValid

public boolean isValid(ClusterNode localNode)

Description copied from interface: SplitBrainDetector

Performs a split-brain check and returns true if local node can reach other members of the cluster.

If this method returns false then HekateFatalErrorPolicy will be applied with ClusterSplitBrainException as a cause.

Specified by:

isValid in interface SplitBrainDetector

Parameters:

localNode - Local node (where the check is performed).

Returns:

true if local node can reach other members of the cluster.

toString

public String toString()

Overrides:

toString in class Object