Package org.apache.cassandra.gms

Class Gossiper

java.lang.Object
org.apache.cassandra.gms.Gossiper
All Implemented Interfaces:
GossiperMBean, IFailureDetectionEventListener, IGossiper
public class Gossiper extends Object implements IFailureDetectionEventListener, GossiperMBean, IGossiper
This module is responsible for Gossiping information for the local endpoint. This abstraction maintains the list of live and dead endpoints. Periodically i.e. every 1 second this module chooses a random node and initiates a round of Gossip with it. A round of Gossip involves 3 rounds of messaging. For instance if node A wants to initiate a round of Gossip with node B it starts off by sending node B a GossipDigestSynMessage. Node B on receipt of this message sends node A a GossipDigestAckMessage. On receipt of this message node A sends node B a GossipDigestAck2Message which completes a round of Gossip. This module as and when it hears one of the three above mentioned messages updates the Failure Detector with the liveness information. Upon hearing a GossipShutdownMessage, this module will instantly mark the remote node as down in the Failure Detector. This class is not threadsafe and any state changes should happen in the gossip stage.

  • Field Details

  • Constructor Details

    • Gossiper

      public Gossiper(boolean registerJmx)

  • Method Details

    • clearUnsafe

      public void clearUnsafe()

    • expireUpgradeFromVersion

      public void expireUpgradeFromVersion()

    • setLastProcessedMessageAt

      public void setLastProcessedMessageAt(long timeInMillis)

    • seenAnySeed

      public boolean seenAnySeed()

    • register

      public void register(IEndpointStateChangeSubscriber subscriber)
      Register for interesting state changes.
      Specified by:
      register in interface IGossiper
      Parameters:
      subscriber - module which implements the IEndpointStateChangeSubscriber

    • unregister

      public void unregister(IEndpointStateChangeSubscriber subscriber)
      Unregister interest for state changes.
      Specified by:
      unregister in interface IGossiper
      Parameters:
      subscriber - module which implements the IEndpointStateChangeSubscriber

    • getLiveMembers

      public Set<InetAddressAndPort> getLiveMembers()
      Returns:
      a list of live gossip participants, including fat clients

    • getLiveTokenOwners

      public Set<InetAddressAndPort> getLiveTokenOwners()
      Returns:
      a list of live ring members.

    • getUnreachableMembers

      public Set<InetAddressAndPort> getUnreachableMembers()
      Returns:
      a list of unreachable gossip participants, including fat clients

    • getUnreachableTokenOwners

      public Set<InetAddressAndPort> getUnreachableTokenOwners()
      Returns:
      a list of unreachable token owners

    • getEndpointDowntime

      public long getEndpointDowntime(InetAddressAndPort ep)

    • runInGossipStageBlocking

      public static void runInGossipStageBlocking(Runnable runnable)

    • convict

      public void convict(InetAddressAndPort endpoint, double phi)
      This method is part of IFailureDetectionEventListener interface. This is invoked by the Failure Detector when it convicts an end point.
      Specified by:
      convict in interface IFailureDetectionEventListener
      Parameters:
      endpoint - end point that is convicted.
      phi - the value of phi with with ep was convicted

    • markAsShutdown

      @Deprecated(since="5.0") protected void markAsShutdown(InetAddressAndPort endpoint)
      Deprecated.
      see CASSANDRA-18913
      This method is used to mark a node as shutdown; that is it gracefully exited on its own and told us about it
      Parameters:
      endpoint - endpoint that has shut itself down

    • markAsShutdown

      protected void markAsShutdown(InetAddressAndPort endpoint, EndpointState remoteState)
      This method is used to mark a node as shutdown; that is it gracefully exited on its own and told us about it
      Parameters:
      endpoint - endpoint that has shut itself down
      remoteState - from the endpoint shutting down

    • removeEndpoint

      public void removeEndpoint(InetAddressAndPort endpoint)
      Removes the endpoint from Gossip but retains endpoint state

    • unsafeAnnulEndpoint

      public void unsafeAnnulEndpoint(InetAddressAndPort endpoint)

    • replacementQuarantine

      public void replacementQuarantine(InetAddressAndPort endpoint)
      Quarantine endpoint specifically for replacement purposes.
      Parameters:
      endpoint -

    • replacedEndpoint

      public void replacedEndpoint(InetAddressAndPort endpoint)
      Remove the Endpoint and evict immediately, to avoid gossiping about this node. This should only be called when a token is taken over by a new IP address.
      Parameters:
      endpoint - The endpoint that has been replaced

    • advertiseRemoving

      public void advertiseRemoving(InetAddressAndPort endpoint, UUID hostId, UUID localHostId)
      This method will begin removing an existing endpoint from the cluster by spoofing its state This should never be called unless this coordinator has had 'removenode' invoked
      Parameters:
      endpoint - - the endpoint being removed
      hostId - - the ID of the host being removed
      localHostId - - my own host ID for replication coordination

    • advertiseTokenRemoved

      public void advertiseTokenRemoved(InetAddressAndPort endpoint, UUID hostId)
      Handles switching the endpoint's state from REMOVING_TOKEN to REMOVED_TOKEN This should only be called after advertiseRemoving
      Parameters:
      endpoint -
      hostId -

    • unsafeAssassinateEndpoint

      public void unsafeAssassinateEndpoint(String address) throws UnknownHostException
      Specified by:
      unsafeAssassinateEndpoint in interface GossiperMBean
      Throws:
      UnknownHostException

    • assassinateEndpoint

      public void assassinateEndpoint(String address) throws UnknownHostException
      Do not call this method unless you know what you are doing. It will try extremely hard to obliterate any endpoint from the ring, even if it does not know about it.
      Specified by:
      assassinateEndpoint in interface GossiperMBean
      Parameters:
      address -
      Throws:
      UnknownHostException

    • isKnownEndpoint

      public boolean isKnownEndpoint(InetAddressAndPort endpoint)

    • getCurrentGenerationNumber

      public int getCurrentGenerationNumber(InetAddressAndPort endpoint)

    • isGossipOnlyMember

      public boolean isGossipOnlyMember(InetAddressAndPort endpoint)

    • isSafeForStartup

      public boolean isSafeForStartup(InetAddressAndPort endpoint, UUID localHostUUID, boolean isBootstrapping, Map<InetAddressAndPort,EndpointState> epStates)
      Check if this node can safely be started and join the ring. If the node is bootstrapping, examines gossip state for any previous status to decide whether it's safe to allow this node to start and bootstrap. If not bootstrapping, compares the host ID that the node itself has (obtained by reading from system.local or generated if not present) with the host ID obtained from gossip for the endpoint address (if any). This latter case prevents a non-bootstrapping, new node from being started with the same address of a previously started, but currently down predecessor.
      Parameters:
      endpoint - - the endpoint to check
      localHostUUID - - the host id to check
      isBootstrapping - - whether the node intends to bootstrap when joining
      epStates - - endpoint states in the cluster
      Returns:
      true if it is safe to start the node, false otherwise

    • getExpireTimeForEndpoint

      protected long getExpireTimeForEndpoint(InetAddressAndPort endpoint)

    • getEndpointStateForEndpoint

      public EndpointState getEndpointStateForEndpoint(InetAddressAndPort ep)
      Specified by:
      getEndpointStateForEndpoint in interface IGossiper

    • inJustRemovedEndpoints

      public boolean inJustRemovedEndpoints(InetAddressAndPort ep)

    • copyEndpointStateForEndpoint

      public EndpointState copyEndpointStateForEndpoint(InetAddressAndPort ep)

    • getEndpoints

      public com.google.common.collect.ImmutableSet<InetAddressAndPort> getEndpoints()

    • getForEndpoint

      public String getForEndpoint(InetAddressAndPort ep, ApplicationState state)

    • getEndpointCount

      public int getEndpointCount()

    • getHostId

      public UUID getHostId(InetAddressAndPort endpoint)

    • getHostId

      public UUID getHostId(InetAddressAndPort endpoint, Map<InetAddressAndPort,EndpointState> epStates)

    • getApplicationState

      public String getApplicationState(InetAddressAndPort endpoint, ApplicationState state)
      The value for the provided application state for the provided endpoint as currently known by this Gossip instance.
      Parameters:
      endpoint - the endpoint from which to get the endpoint state.
      state - the endpoint state to get.
      Returns:
      the value of the application state state for endpoint, or null if either endpoint is not known by Gossip or has no value for state.

    • compareEndpointStartup

      public int compareEndpointStartup(InetAddressAndPort addr1, InetAddressAndPort addr2)
      determine which endpoint started up earlier

    • notifyFailureDetector

      public void notifyFailureDetector(Map<InetAddressAndPort,EndpointState> remoteEpStateMap)
      Specified by:
      notifyFailureDetector in interface IGossiper

    • realMarkAlive

      public void realMarkAlive(InetAddressAndPort addr, EndpointState localState)

    • markDead

      public void markDead(InetAddressAndPort addr, EndpointState localState)

    • isAlive

      public boolean isAlive(InetAddressAndPort endpoint)

    • isDeadState

      public boolean isDeadState(EndpointState epState)

    • isSilentShutdownState

      public boolean isSilentShutdownState(EndpointState epState)

    • isAdministrativelyInactiveState

      public boolean isAdministrativelyInactiveState(EndpointState epState)

    • isAdministrativelyInactiveState

      public boolean isAdministrativelyInactiveState(InetAddressAndPort endpoint)

    • getGossipStatus

      public static String getGossipStatus(EndpointState epState)

    • applyStateLocally

      public void applyStateLocally(Map<InetAddressAndPort,EndpointState> epStateMap)
      Specified by:
      applyStateLocally in interface IGossiper

    • doOnChangeNotifications

      public void doOnChangeNotifications(InetAddressAndPort addr, ApplicationState state, VersionedValue value)

    • start

      public void start(int generationNumber)

    • start

      public void start(int generationNbr, Map<ApplicationState,VersionedValue> preloadLocalStates)
      Start the gossiper with the generation number, preloading the map of application states before starting

    • doShadowRound

      public Map<InetAddressAndPort,EndpointState> doShadowRound()

    • doShadowRound

      public Map<InetAddressAndPort,EndpointState> doShadowRound(Set<InetAddressAndPort> peers)
      Do a single 'shadow' round of gossip by retrieving endpoint states that will be stored exclusively in the map return value, instead of endpointStateMap. Used when preparing to join the ring:
      • when replacing a node, to get and assume its tokens
      • when joining, to check that the local host id matches any previous id for the endpoint address
      Method is synchronized, as we use an in-progress flag to indicate that shadow round must be cleared again by calling maybeFinishShadowRound(InetAddressAndPort, boolean, Map). This will update endpointShadowStateMap with received values, in order to return an immutable copy to the caller of doShadowRound(). Therefor only a single shadow round execution is permitted at the same time.
      Parameters:
      peers - Additional peers to try gossiping with.
      Returns:
      endpoint states gathered during shadow round or empty map

    • reloadSeeds

      public List<String> reloadSeeds()
      JMX interface for triggering an update of the seed node list.
      Specified by:
      reloadSeeds in interface GossiperMBean

    • getSeeds

      public List<String> getSeeds()
      JMX endpoint for getting the list of seeds from the node
      Specified by:
      getSeeds in interface GossiperMBean

    • maybeInitializeLocalState

      public void maybeInitializeLocalState(int generationNbr)

    • forceNewerGeneration

      public void forceNewerGeneration()

    • addSavedEndpoint

      public void addSavedEndpoint(InetAddressAndPort ep)
      Add an endpoint we knew about previously, but whose state is unknown

    • addLocalApplicationState

      public void addLocalApplicationState(ApplicationState applicationState, VersionedValue value)

    • addLocalApplicationStates

      public void addLocalApplicationStates(List<Pair<ApplicationState,VersionedValue>> states)

    • stop

      public void stop()

    • isEnabled

      public boolean isEnabled()

    • sufficientForStartupSafetyCheck

      public boolean sufficientForStartupSafetyCheck(Map<InetAddressAndPort,EndpointState> epStateMap)

    • maybeFinishShadowRound

      protected void maybeFinishShadowRound(InetAddressAndPort respondent, boolean isInShadowRound, Map<InetAddressAndPort,EndpointState> epStateMap)

    • isInShadowRound

      public boolean isInShadowRound()

    • initializeUnreachableNodeUnsafe

      public void initializeUnreachableNodeUnsafe(InetAddressAndPort addr)
      Creates a new dead EndpointState that is empty. This is used during host replacement for edge cases where the seed notified that the endpoint was empty, so need to add such state into gossip explicitly (as empty endpoints are not gossiped outside of the shadow round). see CASSANDRA-16213

    • initializeNodeUnsafe

      public void initializeNodeUnsafe(InetAddressAndPort addr, UUID uuid, int generationNbr)

    • initializeNodeUnsafe

      public void initializeNodeUnsafe(InetAddressAndPort addr, UUID uuid, int netVersion, int generationNbr)

    • injectApplicationState

      public void injectApplicationState(InetAddressAndPort endpoint, ApplicationState state, VersionedValue value)

    • getEndpointDowntime

      public long getEndpointDowntime(String address) throws UnknownHostException
      Specified by:
      getEndpointDowntime in interface GossiperMBean
      Throws:
      UnknownHostException

    • getCurrentGenerationNumber

      public int getCurrentGenerationNumber(String address) throws UnknownHostException
      Specified by:
      getCurrentGenerationNumber in interface GossiperMBean
      Throws:
      UnknownHostException

    • addExpireTimeForEndpoint

      public void addExpireTimeForEndpoint(InetAddressAndPort endpoint, long expireTime)

    • computeExpireTime

      public static long computeExpireTime()

    • getReleaseVersionsWithPort

      public Map<String,List<String>> getReleaseVersionsWithPort()
      Description copied from interface: GossiperMBean
      Returns each node's database release version
      Specified by:
      getReleaseVersionsWithPort in interface GossiperMBean

    • getSchemaVersion

      @Nullable public UUID getSchemaVersion(InetAddressAndPort ep)

    • waitToSettle

      public static void waitToSettle()

    • waitForSchemaAgreement

      public boolean waitForSchemaAgreement(long maxWait, TimeUnit unit, BooleanSupplier abortCondition)
      Blockingly wait for all live nodes to agree on the current schema version.
      Parameters:
      maxWait - maximum time to wait for schema agreement
      unit - TimeUnit of maxWait
      Returns:
      true if agreement was reached, false if not

    • hasMajorVersion3OrUnknownNodes

      public boolean hasMajorVersion3OrUnknownNodes()
      Returns false only if the information about the version of each node in the cluster is available and ALL the nodes are on 4.0+ (regardless of the patch version).

    • isUpgradingFromVersionLowerThan

      public boolean isUpgradingFromVersionLowerThan(CassandraVersion referenceVersion)
      Returns true if there are nodes on version lower than the provided version

    • stopShutdownAndWait

      public void stopShutdownAndWait(long timeout, TimeUnit unit) throws InterruptedException, TimeoutException
      Throws:
      InterruptedException
      TimeoutException

    • getMinVersion

      @Nullable public CassandraVersion getMinVersion(long delay, TimeUnit timeUnit)

    • getLooseEmptyEnabled

      public boolean getLooseEmptyEnabled()
      Specified by:
      getLooseEmptyEnabled in interface GossiperMBean

    • setLooseEmptyEnabled

      public void setLooseEmptyEnabled(boolean enabled)
      Specified by:
      setLooseEmptyEnabled in interface GossiperMBean

    • unsafeSetEnabled

      public void unsafeSetEnabled()

    • unsafeClearRemoteState

      public Collection<InetAddressAndPort> unsafeClearRemoteState()

    • unsafeGossipWith

      public void unsafeGossipWith(InetAddressAndPort ep)

    • unsafeSendShutdown

      public void unsafeSendShutdown(InetAddressAndPort to)

    • unsafeSendLocalEndpointStateTo

      public void unsafeSendLocalEndpointStateTo(InetAddressAndPort ep)

    • compareGossipAndTokenMetadata

      public Map<String,List<String>> compareGossipAndTokenMetadata()
      Description copied from interface: GossiperMBean
      Returns a map of endpoints that don't have matching tokenMetadata to gossip tokens. Values are lists of fixed size two (as Pair is not jmx safe), the first is the gossip tokens, the second tokenMetadata).
      Specified by:
      compareGossipAndTokenMetadata in interface GossiperMBean