ServerManager (Apache HBase - Server 2.2.4 API)

java.lang.Object
- org.apache.hadoop.hbase.master.ServerManager

```
@InterfaceAudience.Private
public class ServerManager
extends Object
```
The ServerManager class manages info about region servers.
Maintains lists of online and dead servers. Processes the startups, shutdowns, and deaths of region servers.
Servers are distinguished in two different ways. A given server has a location, specified by hostname and port, and of which there can only be one online at any given time. A server instance is specified by the location (hostname and port) as well as the startcode (timestamp from when the server was started). This is used to differentiate a restarted instance of a given server from the original instance.
If a sever is known not to be running any more, it is called dead. The dead server needs to be handled by a ServerShutdownHandler. If the handler is not enabled yet, the server can't be handled right away so it is queued up. After the handler is enabled, the server will be submitted to a handler to handle. However, the handler may be just partially enabled. If so, the server cannot be fully processed, and be queued up for further processing. A server is fully processed only after the handler is fully enabled and has completed the handling.

嵌套类概要

嵌套类
限定符和类型类和说明

static class ServerManager.ServerLiveState

嵌套类
限定符和类型	类和说明
`static class`	`ServerManager.ServerLiveState`

字段概要

字段
限定符和类型	字段和说明
`static String`	`WAIT_ON_REGIONSERVERS_INTERVAL`
`static String`	`WAIT_ON_REGIONSERVERS_MAXTOSTART`
`static String`	`WAIT_ON_REGIONSERVERS_MINTOSTART`
`static String`	`WAIT_ON_REGIONSERVERS_TIMEOUT`

构造器概要

构造器
构造器和说明

ServerManager(MasterServices master)
Constructor.

构造器
构造器和说明
`ServerManager(MasterServices master)` Constructor.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法和说明
`boolean`	`addServerToDrainList(ServerName sn)` Add the server to the drain list.
`boolean`	`areDeadServersInProgress()` Checks if any dead servers are currently in progress.
`static void`	`closeRegionSilentlyAndWait(ClusterConnection connection, ServerName server, RegionInfo region, long timeout)` Contacts a region server and waits up to timeout ms to close the region.
`int`	`countOfRegionServers()`
`List<ServerName>`	`createDestinationServersList()` Calls `createDestinationServersList(java.util.List<org.apache.hadoop.hbase.ServerName>)` without server to exclude.
`List<ServerName>`	`createDestinationServersList(List<ServerName> serversToExclude)` Creates a list of possible destinations for a region.
`long`	`expireServer(ServerName serverName)` Expire the passed server.
`double`	`getAverageLoad()` Compute the average load across all region servers.
`DeadServer`	`getDeadServers()`
`List<ServerName>`	`getDrainingServersList()`
`int`	`getInfoPort(ServerName serverName)`
`org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterStatusProtos.RegionStoreSequenceIds`	`getLastFlushedSequenceId(byte[] encodedRegionName)`
`ServerMetrics`	`getLoad(ServerName serverName)`
`Map<ServerName,ServerMetrics>`	`getOnlineServers()`
`List<ServerName>`	`getOnlineServersList()`
`List<ServerName>`	`getOnlineServersListWithPredicator(List<ServerName> keys, Predicate<ServerMetrics> idleServerPredicator)`
`org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.AdminService.BlockingInterface`	`getRsAdmin(ServerName sn)`
`String`	`getVersion(ServerName serverName)` May return "0.0.0" when server is not online
`int`	`getVersionNumber(ServerName serverName)` May return 0 when server is not online.
`boolean`	`isClusterShutdown()`
`boolean`	`isRegionInServerManagerStates(RegionInfo hri)`
`boolean`	`isServerDead(ServerName serverName)` Check if a server is known to be dead.
`ServerManager.ServerLiveState`	`isServerKnownAndOnline(ServerName serverName)`
`boolean`	`isServerOnline(ServerName serverName)`
`void`	`moveFromOnlineToDeadServers(ServerName sn)`
`void`	`regionServerReport(ServerName sn, ServerMetrics sl)`
`void`	`registerListener(ServerListener listener)` Add the listener to the notification list.
`void`	`removeRegion(RegionInfo regionInfo)` Called by delete table and similar to notify the ServerManager that a region was removed.
`void`	`removeRegions(List<RegionInfo> regions)` Called by delete table and similar to notify the ServerManager that a region was removed.
`boolean`	`removeServerFromDrainList(ServerName sn)`
`void`	`sendRegionWarmup(ServerName server, RegionInfo region)` Sends a WARMUP RPC to the specified server to warmup the specified region.
`void`	`shutdownCluster()`
`void`	`stop()` Stop the ServerManager.
`boolean`	`unregisterListener(ServerListener listener)` Remove the listener from the notification list.
`void`	`waitForRegionServers(MonitoredTask status)` Wait for the region servers to report in.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - WAIT_ON_REGIONSERVERS_MAXTOSTART
```
public static final String WAIT_ON_REGIONSERVERS_MAXTOSTART
```
    另请参阅:
    
    常量字段值
  - WAIT_ON_REGIONSERVERS_MINTOSTART
```
public static final String WAIT_ON_REGIONSERVERS_MINTOSTART
```
    另请参阅:
    
    常量字段值
  - WAIT_ON_REGIONSERVERS_TIMEOUT
```
public static final String WAIT_ON_REGIONSERVERS_TIMEOUT
```
    另请参阅:
    
    常量字段值
  - WAIT_ON_REGIONSERVERS_INTERVAL
```
public static final String WAIT_ON_REGIONSERVERS_INTERVAL
```
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - ServerManager
```
public ServerManager(MasterServices master)
```
    Constructor.
- 方法详细资料
  - registerListener
```
public void registerListener(ServerListener listener)
```
    Add the listener to the notification list.
    
    参数:
    
    listener - The ServerListener to register
  - unregisterListener
```
public boolean unregisterListener(ServerListener listener)
```
    Remove the listener from the notification list.
    
    参数:
    
    listener - The ServerListener to unregister
  - regionServerReport
```
public void regionServerReport(ServerName sn,
                               ServerMetrics sl)
                        throws YouAreDeadException
```
    抛出:
    
    YouAreDeadException
  - getLastFlushedSequenceId
```
public org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterStatusProtos.RegionStoreSequenceIds getLastFlushedSequenceId(byte[] encodedRegionName)
```
  - getLoad
```
public ServerMetrics getLoad(ServerName serverName)
```
    参数:
    
    serverName -
    
    返回:
    
    ServerMetrics if serverName is known else null
  - getAverageLoad
```
public double getAverageLoad()
```
    Compute the average load across all region servers. Currently, this uses a very naive computation - just uses the number of regions being served, ignoring stats about number of requests.
    
    返回:
    
    the average load
  - countOfRegionServers
```
public int countOfRegionServers()
```
    返回:
    
    the count of active regionservers
  - getOnlineServers
```
public Map<ServerName,ServerMetrics> getOnlineServers()
```
    返回:
    
    Read-only map of servers to serverinfo
  - getDeadServers
```
public DeadServer getDeadServers()
```
  - areDeadServersInProgress
```
public boolean areDeadServersInProgress()
```
    Checks if any dead servers are currently in progress.
    
    返回:
    
    true if any RS are being processed as dead, false if not
  - expireServer
```
public long expireServer(ServerName serverName)
```
    Expire the passed server. Add it to list of dead servers and queue a shutdown processing.
    
    返回:
    
    pid if we queued a ServerCrashProcedure else Procedure.NO_PROC_ID if we did not (could happen for many reasons including the fact that its this server that is going down or we already have queued an SCP for this server or SCP processing is currently disabled because we are in startup phase).
  - moveFromOnlineToDeadServers
```
public void moveFromOnlineToDeadServers(ServerName sn)
```
  - removeServerFromDrainList
```
public boolean removeServerFromDrainList(ServerName sn)
```
  - addServerToDrainList
```
public boolean addServerToDrainList(ServerName sn)
```
    Add the server to the drain list.
    
    参数:
    
    sn -
    
    返回:
    
    True if the server is added or the server is already on the drain list.
  - sendRegionWarmup
```
public void sendRegionWarmup(ServerName server,
                             RegionInfo region)
```
    Sends a WARMUP RPC to the specified server to warmup the specified region.
    A region server could reject the close request because it either does not have the specified region or the region is being split.
    
    参数:
    
    server - server to warmup a region
    
    region - region to warmup
  - closeRegionSilentlyAndWait
```
public static void closeRegionSilentlyAndWait(ClusterConnection connection,
                                              ServerName server,
                                              RegionInfo region,
                                              long timeout)
                                       throws IOException,
                                              InterruptedException
```
    Contacts a region server and waits up to timeout ms to close the region. This bypasses the active hmaster.
    
    抛出:
    
    IOException
    
    InterruptedException
  - getRsAdmin
```
public org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.AdminService.BlockingInterface getRsAdmin(ServerName sn)
                                                                                                        throws IOException
```
    参数:
    
    sn -
    
    返回:
    
    Admin interface for the remote regionserver named sn
    
    抛出:
    
    IOException
    
    RetriesExhaustedException - wrapping a ConnectException if failed
  - waitForRegionServers
```
public void waitForRegionServers(MonitoredTask status)
                          throws InterruptedException
```
    Wait for the region servers to report in. We will wait until one of this condition is met: - the master is stopped - the 'hbase.master.wait.on.regionservers.maxtostart' number of region servers is reached - the 'hbase.master.wait.on.regionservers.mintostart' is reached AND there have been no new region server in for 'hbase.master.wait.on.regionservers.interval' time AND the 'hbase.master.wait.on.regionservers.timeout' is reached
    
    抛出:
    
    InterruptedException
  - getOnlineServersList
```
public List<ServerName> getOnlineServersList()
```
    返回:
    
    A copy of the internal list of online servers.
  - getOnlineServersListWithPredicator
```
public List<ServerName> getOnlineServersListWithPredicator(List<ServerName> keys,
                                                           Predicate<ServerMetrics> idleServerPredicator)
```
    参数:
    
    keys - The target server name
    
    idleServerPredicator - Evaluates the server on the given load
    
    返回:
    
    A copy of the internal list of online servers matched by the predicator
  - getDrainingServersList
```
public List<ServerName> getDrainingServersList()
```
    返回:
    
    A copy of the internal list of draining servers.
  - isServerOnline
```
public boolean isServerOnline(ServerName serverName)
```
  - isServerKnownAndOnline
```
public ServerManager.ServerLiveState isServerKnownAndOnline(ServerName serverName)
```
    返回:
    
    whether the server is online, dead, or unknown.
  - isServerDead
```
public boolean isServerDead(ServerName serverName)
```
    Check if a server is known to be dead. A server can be online, or known to be dead, or unknown to this manager (i.e, not online, not known to be dead either. it is simply not tracked by the master any more, for example, a very old previous instance).
  - shutdownCluster
```
public void shutdownCluster()
```
  - isClusterShutdown
```
public boolean isClusterShutdown()
```
  - stop
```
public void stop()
```
    Stop the ServerManager.
  - createDestinationServersList
```
public List<ServerName> createDestinationServersList(List<ServerName> serversToExclude)
```
    Creates a list of possible destinations for a region. It contains the online servers, but not the draining or dying servers.
    
    参数:
    
    serversToExclude - can be null if there is no server to exclude
  - createDestinationServersList
```
public List<ServerName> createDestinationServersList()
```
    Calls createDestinationServersList(java.util.List<org.apache.hadoop.hbase.ServerName>) without server to exclude.
  - removeRegion
```
public void removeRegion(RegionInfo regionInfo)
```
    Called by delete table and similar to notify the ServerManager that a region was removed.
  - isRegionInServerManagerStates
```
public boolean isRegionInServerManagerStates(RegionInfo hri)
```
  - removeRegions
```
public void removeRegions(List<RegionInfo> regions)
```
    Called by delete table and similar to notify the ServerManager that a region was removed.
  - getVersionNumber
```
public int getVersionNumber(ServerName serverName)
```
    May return 0 when server is not online.
  - getVersion
```
public String getVersion(ServerName serverName)
```
    May return "0.0.0" when server is not online
  - getInfoPort
```
public int getInfoPort(ServerName serverName)
```

类 ServerManager

嵌套类概要

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

WAIT_ON_REGIONSERVERS_MAXTOSTART

WAIT_ON_REGIONSERVERS_MINTOSTART

WAIT_ON_REGIONSERVERS_TIMEOUT

WAIT_ON_REGIONSERVERS_INTERVAL

构造器详细资料

ServerManager

方法详细资料

registerListener

unregisterListener

regionServerReport

getLastFlushedSequenceId

getLoad

getAverageLoad

countOfRegionServers

getOnlineServers

getDeadServers

areDeadServersInProgress

expireServer

moveFromOnlineToDeadServers

removeServerFromDrainList

addServerToDrainList

sendRegionWarmup

closeRegionSilentlyAndWait

getRsAdmin

waitForRegionServers

getOnlineServersList

getOnlineServersListWithPredicator

getDrainingServersList

isServerOnline

isServerKnownAndOnline

isServerDead

shutdownCluster

isClusterShutdown

stop

createDestinationServersList

createDestinationServersList

removeRegion

isRegionInServerManagerStates

removeRegions

getVersionNumber

getVersion

getInfoPort