Package com.hazelcast.jet.config
Class InstanceConfig
java.lang.Object
com.hazelcast.jet.config.InstanceConfig
public class InstanceConfig extends Object
General configuration options pertaining to a Jet instance.
- Since:
- 3.0
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Field Summary
Fields Modifier and Type Field Description static int
DEFAULT_BACKUP_COUNT
The default value of thebackup-count
static int
DEFAULT_FLOW_CONTROL_PERIOD_MS
The default value of theflow-control period
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Constructor Summary
Constructors Constructor Description InstanceConfig()
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Method Summary
Modifier and Type Method Description int
getBackupCount()
Returns thenumber of backups
used for job metadata and snapshots.int
getCooperativeThreadCount()
Returns the number of cooperative execution threads.int
getFlowControlPeriodMs()
Returns theflow-control period
in milliseconds.long
getScaleUpDelayMillis()
Returns the scale-up delay, seesetScaleUpDelayMillis(long)
.boolean
isLosslessRestartEnabled()
Returns if lossless restart is enabled, seesetLosslessRestartEnabled(boolean)
.InstanceConfig
setBackupCount(int newBackupCount)
Sets the number of backups that Jet will maintain for the job metadata and snapshots.InstanceConfig
setCooperativeThreadCount(int size)
Sets the number of threads each cluster member will use to execute Jet jobs.InstanceConfig
setFlowControlPeriodMs(int flowControlPeriodMs)
While executing a Jet job there is the issue of regulating the rate at which one member of the cluster sends data to another member.InstanceConfig
setLosslessRestartEnabled(boolean enabled)
Sets whether lossless job restart is enabled for the node.InstanceConfig
setScaleUpDelayMillis(long millis)
Sets the delay after which auto-scaled jobs will restart if a new member is added to the cluster.
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Field Details
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DEFAULT_FLOW_CONTROL_PERIOD_MS
public static final int DEFAULT_FLOW_CONTROL_PERIOD_MSThe default value of theflow-control period
.- See Also:
- Constant Field Values
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DEFAULT_BACKUP_COUNT
public static final int DEFAULT_BACKUP_COUNTThe default value of thebackup-count
- See Also:
- Constant Field Values
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Constructor Details
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InstanceConfig
public InstanceConfig()
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Method Details
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setCooperativeThreadCount
Sets the number of threads each cluster member will use to execute Jet jobs. This refers only to threads executing cooperative processors; each blocking processor is assigned its own thread. -
getCooperativeThreadCount
public int getCooperativeThreadCount()Returns the number of cooperative execution threads. -
setFlowControlPeriodMs
While executing a Jet job there is the issue of regulating the rate at which one member of the cluster sends data to another member. The receiver will regularly report to each sender how much more data it is allowed to send over a given DAG edge. This method sets the length (in milliseconds) of the interval between flow-control ("ack") packets. -
getFlowControlPeriodMs
public int getFlowControlPeriodMs()Returns theflow-control period
in milliseconds. -
setBackupCount
Sets the number of backups that Jet will maintain for the job metadata and snapshots. Each backup is on another cluster member; all backup write operations must complete before the overall write operation can complete. The maximum allowed number of backups is 6 and the default is 1.For example, if you set the backup count to 2, Jet will replicate all the job metadata and snapshot data to two other members. If one or two members of the cluster fail, Jet can recover the data from the snapshot and continue executing the job on the remaining members without loss.
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getBackupCount
public int getBackupCount()Returns thenumber of backups
used for job metadata and snapshots. -
setScaleUpDelayMillis
Sets the delay after which auto-scaled jobs will restart if a new member is added to the cluster. The default is 10 seconds. Has no effect on jobs with auto scaling disabled.- Parameters:
millis
- the delay, in milliseconds- Returns:
- this instance for fluent API
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getScaleUpDelayMillis
public long getScaleUpDelayMillis()Returns the scale-up delay, seesetScaleUpDelayMillis(long)
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isLosslessRestartEnabled
public boolean isLosslessRestartEnabled()Returns if lossless restart is enabled, seesetLosslessRestartEnabled(boolean)
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setLosslessRestartEnabled
Sets whether lossless job restart is enabled for the node. With lossless restart you can restart the whole cluster without losing the jobs and their state. The feature is implemented on top of the Hot Restart feature of Hazelcast IMDG which persists the data to disk.If enabled, you have to also configure Hot Restart:
JetConfig jetConfig = new JetConfig(); jetConfig.getInstanceConfig().setLosslessRestartEnabled(true); jetConfig.getHazelcastConfig().getHotRestartPersistenceConfig() .setEnabled(true) .setBaseDir(new File("/mnt/hot-restart")) .setParallelism(2);
Note: the snapshots exported using
Job.exportSnapshot(java.lang.String)
will also have Hot Restart storage enabled.Feature is disabled by default. If you enable this option in open-source Hazelcast Jet, the member will fail to start, you need Jet Enterprise to run it and obtain a license from Hazelcast.
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