voldemort.store.rebalancing
Class RedirectingStore

java.lang.Object
  voldemort.store.AbstractStore<K,V,T>
      voldemort.store.DelegatingStore<ByteArray,byte[],byte[]>
          voldemort.store.rebalancing.RedirectingStore

All Implemented Interfaces:

Store<ByteArray,byte[],byte[]>

public class RedirectingStore
extends DelegatingStore<ByteArray,byte[],byte[]>

The RedirectingStore extends DelegatingStore

If current server_state is MetadataStore.VoldemortState.REBALANCING_MASTER_SERVER then handle incoming requests in the following way, if the key belongs to a partition that this server is currently stealing. Such a server has what we call a 'proxy node', which is the server which owned that partition as the exact same type of replica in the same zone, as per the old cluster topology. 1. getVersions/get
If the server contains the key locally, then serve it directly. Else, fetch from proxy node, update local storage and then serve it off that. 2. getAll
Similarly, for keys that exist locally, serve it off directly. Else, fetch-update the missing keys from proxyNode and then serve them off local storage. 3. put
First write it to local storage, then submit a async put() to the proxy node, so we can safely abort the rebalancing if we have to. 4. delete
:) :) :)

Constructor Summary

RedirectingStore(Store<ByteArray,byte[],byte[]> innerStore, MetadataStore metadata, StoreRepository storeRepository, FailureDetector detector, SocketStoreFactory storeFactory, java.util.concurrent.ExecutorService proxyPutWorkerPool, ProxyPutStats proxyPutStats)

Method Summary

protected void	checkNodeAvailable(Node proxyNode)
boolean	delete(ByteArray key, Version version) TODO : Handle delete correctly.
java.util.List<Versioned<byte[]>>	get(ByteArray key, byte[] transforms) Get the value associated with the given key
java.util.Map<ByteArray,java.util.List<Versioned<byte[]>>>	getAll(java.lang.Iterable<ByteArray> keys, java.util.Map<ByteArray,byte[]> transforms) Get the values associated with the given keys and returns them in a Map of keys to a list of versioned values.
boolean	getIsRedirectingStoreEnabled()
protected MetadataStore	getMetadataStore()
ProxyPutStats	getProxyPutStats()
protected Store<ByteArray,byte[],byte[]>	getRedirectingSocketStore(java.lang.String storeName, int proxyNodeId) Get the SocketStore to redirect to for the proxy node, creating one if needed.
java.util.List<Version>	getVersions(ByteArray key) Get the versions associated with the given key.
boolean	isServerRebalancing()
void	put(ByteArray key, Versioned<byte[]> value, byte[] transforms) Associate the value with the key and version in this store
protected void	recordException(Node node, long startNs, UnreachableStoreException e)
protected void	recordSuccess(Node node, long startNs)
protected void	reportProxyPutFailure()
protected void	reportProxyPutSuccess()
void	setIsRedirectingStoreEnabled(boolean isRedirectingStoreEnabled)

Methods inherited from class voldemort.store.DelegatingStore

close, delete, get, getAll, getCapability, getInnerStore, put, toString

Methods inherited from class voldemort.store.AbstractStore

getName

Methods inherited from class java.lang.Object

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

Constructor Detail

RedirectingStore

public RedirectingStore(Store<ByteArray,byte[],byte[]> innerStore,
                        MetadataStore metadata,
                        StoreRepository storeRepository,
                        FailureDetector detector,
                        SocketStoreFactory storeFactory,
                        java.util.concurrent.ExecutorService proxyPutWorkerPool,
                        ProxyPutStats proxyPutStats)

Method Detail

setIsRedirectingStoreEnabled

public void setIsRedirectingStoreEnabled(boolean isRedirectingStoreEnabled)

getIsRedirectingStoreEnabled

public boolean getIsRedirectingStoreEnabled()

get

public java.util.List<Versioned<byte[]>> get(ByteArray key,
                                             byte[] transforms)
                                      throws VoldemortException

Description copied from interface: Store

Get the value associated with the given key

Specified by:

get in interface Store<ByteArray,byte[],byte[]>

Overrides:

get in class DelegatingStore<ByteArray,byte[],byte[]>

Parameters:

key - The key to check for

Returns:

The value associated with the key or an empty list if no values are found.

Throws:

VoldemortException

getVersions

public java.util.List<Version> getVersions(ByteArray key)

Description copied from interface: Store

Get the versions associated with the given key. This is used in a put call to write a new value for this key

Specified by:

getVersions in interface Store<ByteArray,byte[],byte[]>

Overrides:

getVersions in class DelegatingStore<ByteArray,byte[],byte[]>

Parameters:

key - The key to retrieve the versions for

Returns:

List of Versions associated with this key.

getAll

public java.util.Map<ByteArray,java.util.List<Versioned<byte[]>>> getAll(java.lang.Iterable<ByteArray> keys,
                                                                         java.util.Map<ByteArray,byte[]> transforms)
                                                                  throws VoldemortException

Description copied from interface: Store

Get the values associated with the given keys and returns them in a Map of keys to a list of versioned values. Note that the returned map will only contain entries for the keys which have a value associated with them.

Specified by:

getAll in interface Store<ByteArray,byte[],byte[]>

Overrides:

getAll in class DelegatingStore<ByteArray,byte[],byte[]>

Parameters:

keys - The keys to check for.

Returns:

A Map of keys to a list of versioned values.

Throws:

VoldemortException

put

public void put(ByteArray key,
                Versioned<byte[]> value,
                byte[] transforms)
         throws VoldemortException

Description copied from interface: Store

Associate the value with the key and version in this store

Specified by:

put in interface Store<ByteArray,byte[],byte[]>

Overrides:

put in class DelegatingStore<ByteArray,byte[],byte[]>

Parameters:

key - The key to use

value - The value to store and its version.

Throws:

VoldemortException

delete

public boolean delete(ByteArray key,
                      Version version)
               throws VoldemortException

TODO : Handle delete correctly.

The options are:

1. Delete locally and on remote node as well. The issue is cursor is open in READ_UNCOMMITED mode while rebalancing and can push the value back.
2. Keep the operation in separate slop store and apply all deletes after rebalancing.
3. Do not worry about deletes for now, Voldemort in general has an issue that if node goes down during a delete, we will still keep the old version.

Specified by:

delete in interface Store<ByteArray,byte[],byte[]>

Overrides:

delete in class DelegatingStore<ByteArray,byte[],byte[]>

Parameters:

key - The key to delete

version - The current value of the key

Returns:

True if anything was deleted

Throws:

VoldemortException

isServerRebalancing

public boolean isServerRebalancing()

checkNodeAvailable

protected void checkNodeAvailable(Node proxyNode)

getRedirectingSocketStore

protected Store<ByteArray,byte[],byte[]> getRedirectingSocketStore(java.lang.String storeName,
                                                                   int proxyNodeId)

Get the SocketStore to redirect to for the proxy node, creating one if needed.

Parameters:

storeName - Name of the store

proxyNodeId - proxy node id

Returns:

SocketStore object for storeName and proxyNodeId

recordException

protected void recordException(Node node,
                               long startNs,
                               UnreachableStoreException e)

recordSuccess

protected void recordSuccess(Node node,
                             long startNs)

getMetadataStore

protected MetadataStore getMetadataStore()

reportProxyPutFailure

protected void reportProxyPutFailure()

reportProxyPutSuccess

protected void reportProxyPutSuccess()

getProxyPutStats

public ProxyPutStats getProxyPutStats()