Package org.apache.geode.cache.util

Class AutoBalancer

  • java.lang.Object
    • org.apache.geode.cache.util.AutoBalancer
  • All Implemented Interfaces:
    Declarable
    @Experimental("The autobalancer may be removed or the API may change in future releases")
public class AutoBalancer
extends java.lang.Object
implements Declarable
    Re-balancing operation relocates data from heavily loaded members to lightly loaded members. In most cases, the decision to re-balance is based on the size of the member and a few other statistics. AutoBalancer monitors these statistics and if necessary, triggers a re-balancing request. Auto-Balancing is expected to prevent failures and data loss.

    This implementation is based on ConfigInitialization implementation. By default auto-balancing is disabled. A user needs to configure AutoBalancer during cache initialization GemFireCache.getInitializer()

    In a cluster only one member owns auto-balancing responsibility. This is achieved by grabbing a distributed lock. In case of a failure a new member will grab the lock and manage auto balancing.

    AutoBalancer can be controlled using the following configurations

    1. SCHEDULE
    2. TBD THRESHOLDS

    • Constructor Summary

      Constructors 
      Constructor Description
      AutoBalancer()  
      AutoBalancer​(org.apache.geode.cache.util.AutoBalancer.AuditScheduler scheduler, org.apache.geode.cache.util.AutoBalancer.OOBAuditor auditor, org.apache.geode.cache.util.AutoBalancer.TimeProvider clock, org.apache.geode.cache.util.AutoBalancer.CacheOperationFacade cacheFacade)  

    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      void destroy()  
      org.apache.geode.cache.util.AutoBalancer.CacheOperationFacade getCacheOperationFacade()  
      void init​(java.util.Properties props)
      Deprecated.
      as of Geode 1.5 use initialize instead.
      void initialize​(Cache cache, java.util.Properties props)
      Initializes a user-defined object, owned by the given cache, using the given properties.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • SCHEDULE

        public static final java.lang.String SCHEDULE
        Use this configuration to manage out-of-balance audit frequency. If the auditor finds the system to be out-of-balance, it will trigger re-balancing. Any valid cron string is accepted. The sub-expressions represent the following:
        1. Seconds
        2. Minutes
        3. Hours
        4. Day-of-Month
        5. Month
        6. Day-of-Week
        7. Year (optional field)

        For. e.g. 0 0 * * * ? for auditing the system every hour

        See Also:
        Constant Field Values

      • SIZE_THRESHOLD_PERCENT

        public static final java.lang.String SIZE_THRESHOLD_PERCENT
        Use this configuration to manage re-balance invocation. Rebalance operation will be triggered if the total number of bytes rebalance operation may move is more than this threshold, in percentage of the total data size.

        Default value DEFAULT_SIZE_THRESHOLD_PERCENT

        See Also:
        Constant Field Values

      • DEFAULT_SIZE_THRESHOLD_PERCENT

        public static final int DEFAULT_SIZE_THRESHOLD_PERCENT
        Default value of SIZE_THRESHOLD_PERCENT. If 10% of data is misplaced, its a good time to redistribute buckets
        See Also:
        Constant Field Values

      • MINIMUM_SIZE

        public static final java.lang.String MINIMUM_SIZE
        In the initial data load phases, SIZE_THRESHOLD_PERCENT based rebalance invocation may be unnecessary. Rebalance should not be triggered if the total data size managed by cluster is too small. Rebalance operation will be triggered if the total number of bytes rebalance operation may move is more than this number of bytes.

        Default value DEFAULT_MINIMUM_SIZE

        See Also:
        Constant Field Values

      • DEFAULT_MINIMUM_SIZE

        public static final int DEFAULT_MINIMUM_SIZE
        Default value of MINIMUM_SIZE. In the initial data load phases, SIZE_THRESHOLD_PERCENT based rebalance invocation may be unnecessary. Do not rebalance if the data to be moved is less than 100MB
        See Also:
        Constant Field Values

      • AUTO_BALANCER_LOCK_SERVICE_NAME

        public static final java.lang.String AUTO_BALANCER_LOCK_SERVICE_NAME
        Name of the DistributedLockService that AutoBalancer will use to guard against concurrent maintenance activity
        See Also:
        Constant Field Values

      • AUTO_BALANCER_LOCK

        public static final java.lang.Object AUTO_BALANCER_LOCK

    • Constructor Detail

      • AutoBalancer

        public AutoBalancer()

      • AutoBalancer

        public AutoBalancer​(org.apache.geode.cache.util.AutoBalancer.AuditScheduler scheduler,
                    org.apache.geode.cache.util.AutoBalancer.OOBAuditor auditor,
                    org.apache.geode.cache.util.AutoBalancer.TimeProvider clock,
                    org.apache.geode.cache.util.AutoBalancer.CacheOperationFacade cacheFacade)

    • Method Detail

      • initialize

        public void initialize​(Cache cache,
                       java.util.Properties props)
        Description copied from interface: Declarable
        Initializes a user-defined object, owned by the given cache, using the given properties. Note that any uncaught exception thrown by this method will cause the Cache initialization to fail. Note that if this method is implemented then the deprecated init method should not be implemented. The product will call both methods assuming that only one will have a non-default implementation.

        Note that this method is only called when a Cache is created using gfsh cluster configuration or a declarative XML file. It will not be called when a Cache is created without XML using the Java APIs directly.

        Specified by:
        initialize in interface Declarable
        Parameters:
        cache - the cache that owns this declarable
        props - Contains the parameters declared in the declarative xml file.

      • init

        @Deprecated
public void init​(java.util.Properties props)
        Deprecated.
        as of Geode 1.5 use initialize instead.
        Description copied from interface: Declarable
        Initializes a user-defined object using the given properties. Note that any uncaught exception thrown by this method will cause the Cache initialization to fail.
        Specified by:
        init in interface Declarable
        Parameters:
        props - Contains the parameters declared in the declarative xml file.

      • getCacheOperationFacade

        public org.apache.geode.cache.util.AutoBalancer.CacheOperationFacade getCacheOperationFacade()

      • destroy

        public void destroy()