ClusterStatusPublisher (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.ScheduledChore
- - org.apache.hadoop.hbase.master.ClusterStatusPublisher

All Implemented Interfaces:

Runnable
```
@InterfaceAudience.Private
public class ClusterStatusPublisher
extends ScheduledChore
```
Class to publish the cluster status to the client. This allows them to know immediately the dead region servers, hence to cut the connection they have with them, eventually stop waiting on the socket. This improves the mean time to recover, and as well allows to increase on the client the different timeouts, as the dead servers will be detected separately.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ClusterStatusPublisher.MulticastPublisher

static interface ClusterStatusPublisher.Publisher

Nested Classes
Modifier and Type	Class and Description
`static class`	`ClusterStatusPublisher.MulticastPublisher`
`static interface`	`ClusterStatusPublisher.Publisher`

Field Summary

Fields
Modifier and Type	Field and Description
`private boolean`	`connected`
`static int`	`DEFAULT_STATUS_PUBLISH_PERIOD`
`static Class<? extends ClusterStatusPublisher.Publisher>`	`DEFAULT_STATUS_PUBLISHER_CLASS`
`private long`	`lastMessageTime`
`private ConcurrentMap<ServerName,Integer>`	`lastSent`
`private HMaster`	`master`
`static int`	`MAX_SERVER_PER_MESSAGE` We want to limit the size of the protobuf message sent, do fit into a single packet.
`private int`	`messagePeriod`
`static int`	`NB_SEND` If a server dies, we're sending the information multiple times in case a receiver misses the message.
`private ClusterStatusPublisher.Publisher`	`publisher`
`static String`	`STATUS_PUBLISH_PERIOD` The minimum time between two status messages, in milliseconds.
`static String`	`STATUS_PUBLISHER_CLASS` The implementation class used to publish the status.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`ClusterStatusPublisher()`
	`ClusterStatusPublisher(HMaster master, org.apache.hadoop.conf.Configuration conf, Class<? extends ClusterStatusPublisher.Publisher> publisherClass)`

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`chore()` The task to execute on each scheduled execution of the Chore
`protected void`	`cleanup()` Override to run cleanup tasks when the Chore encounters an error and must stop running
`protected List<ServerName>`	`generateDeadServersListToSend()` Create the dead server to send.
`protected List<Pair<ServerName,Long>>`	`getDeadServers(long since)` Get the servers which died since a given timestamp.

Methods inherited from class org.apache.hadoop.hbase.ScheduledChore
cancel, cancel, choreForTesting, getInitialDelay, getName, getPeriod, getStopper, getTimeUnit, initialChore, isInitialChoreComplete, isScheduled, run, toString, triggerNow

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - STATUS_PUBLISHER_CLASS
```
public static final String STATUS_PUBLISHER_CLASS
```
    The implementation class used to publish the status. Default is null (no publish). Use org.apache.hadoop.hbase.master.ClusterStatusPublisher.MulticastPublisher to multicast the status.
    
    See Also:
    Constant Field Values
  - DEFAULT_STATUS_PUBLISHER_CLASS
```
public static final Class<? extends ClusterStatusPublisher.Publisher> DEFAULT_STATUS_PUBLISHER_CLASS
```
  - STATUS_PUBLISH_PERIOD
```
public static final String STATUS_PUBLISH_PERIOD
```
    The minimum time between two status messages, in milliseconds.
    
    See Also:
    Constant Field Values
  - DEFAULT_STATUS_PUBLISH_PERIOD
```
public static final int DEFAULT_STATUS_PUBLISH_PERIOD
```
    See Also:
    Constant Field Values
  - lastMessageTime
```
private long lastMessageTime
```
  - master
```
private final HMaster master
```
  - messagePeriod
```
private final int messagePeriod
```
  - lastSent
```
private final ConcurrentMap<ServerName,Integer> lastSent
```
  - publisher
```
private ClusterStatusPublisher.Publisher publisher
```
  - connected
```
private boolean connected
```
  - MAX_SERVER_PER_MESSAGE
```
public static final int MAX_SERVER_PER_MESSAGE
```
    We want to limit the size of the protobuf message sent, do fit into a single packet. a reasonable size for ip / ethernet is less than 1Kb.
    
    See Also:
    Constant Field Values
  - NB_SEND
```
public static final int NB_SEND
```
    If a server dies, we're sending the information multiple times in case a receiver misses the message.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - ClusterStatusPublisher
```
public ClusterStatusPublisher(HMaster master,
                      org.apache.hadoop.conf.Configuration conf,
                      Class<? extends ClusterStatusPublisher.Publisher> publisherClass)
                       throws IOException
```
    Throws:
    
    IOException
  - ClusterStatusPublisher
```
protected ClusterStatusPublisher()
```
- Method Detail
  - chore
```
protected void chore()
```
    Description copied from class: ScheduledChore
    
    The task to execute on each scheduled execution of the Chore
    
    Specified by:
    
    chore in class ScheduledChore
  - cleanup
```
protected void cleanup()
```
    Description copied from class: ScheduledChore
    
    Override to run cleanup tasks when the Chore encounters an error and must stop running
    
    Overrides:
    
    cleanup in class ScheduledChore
  - generateDeadServersListToSend
```
protected List<ServerName> generateDeadServersListToSend()
```
    Create the dead server to send. A dead server is sent NB_SEND times. We send at max MAX_SERVER_PER_MESSAGE at a time. if there are too many dead servers, we send the newly dead first.
  - getDeadServers
```
protected List<Pair<ServerName,Long>> getDeadServers(long since)
```
    Get the servers which died since a given timestamp. protected because it can be subclassed by the tests.

Class ClusterStatusPublisher

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.ScheduledChore

Methods inherited from class java.lang.Object

Field Detail

STATUS_PUBLISHER_CLASS

DEFAULT_STATUS_PUBLISHER_CLASS

STATUS_PUBLISH_PERIOD

DEFAULT_STATUS_PUBLISH_PERIOD

lastMessageTime

master

messagePeriod

lastSent

publisher

connected

MAX_SERVER_PER_MESSAGE

NB_SEND

Constructor Detail

ClusterStatusPublisher

ClusterStatusPublisher

Method Detail

chore

cleanup

generateDeadServersListToSend

getDeadServers