com.mongodb
Class WriteConcern

java.lang.Object
  com.mongodb.WriteConcern

Direct Known Subclasses:

WriteConcern.Majority

public class WriteConcern
extends Object

WriteConcern control the write behavior for with various options, as well as exception raising on error conditions.

w

• -1 = don't even report network errors
• 0 = default, don't call getLastError by default
• 1 = basic, call getLastError, but don't wait for slaves
• 2+= wait for slaves

wtimeout how long to wait for slaves before failing

• 0 = indefinite
• > 0 = ms to wait

fsync force fsync to disk

MongoDB Doc Links

• databases

Nested Class Summary

static class

WriteConcern.Majority

Field Summary

static WriteConcern	FSYNC_SAFE Exceptions are raised for network issues, and server errors; the write operation waits for the server to flush the data to disk
static WriteConcern	JOURNAL_SAFE Exceptions are raised for network issues, and server errors; the write operation waits for the server to group commit to the journal file on disk
static WriteConcern	MAJORITY Exceptions are raised for network issues, and server errors; waits on a majority of servers for the write operation
static WriteConcern	NONE No exceptions are raised, even for network issues
static WriteConcern	NORMAL Exceptions are raised for network issues, but not server errors
static WriteConcern	REPLICAS_SAFE Exceptions are raised for network issues, and server errors; waits for at least 2 servers for the write operation
static WriteConcern	SAFE Exceptions are raised for network issues, and server errors; waits on a server for the write operation

Constructor Summary

WriteConcern()
Default constructor keeping all options as default

WriteConcern(boolean fsync)
Calls WriteConcern(int, int, boolean) with w=1 and wtimeout=0

WriteConcern(int w)
Calls WriteConcern(int, int, boolean) with wtimeout=0 and fsync=false

WriteConcern(int w, int wtimeout)
Calls WriteConcern(int, int, boolean) with fsync=false

WriteConcern(int w, int wtimeout, boolean fsync)
Creates a WriteConcern object.

WriteConcern(int w, int wtimeout, boolean fsync, boolean j)
Creates a WriteConcern object.

WriteConcern(int w, int wtimeout, boolean fsync, boolean j, boolean continueInsertOnError)
Creates a WriteConcern object.

WriteConcern(String w)
Tag based Write Concern with wtimeout=0, fsync=false, and j=false

WriteConcern(String w, boolean j)
Tag based Write Concern with configgable j and wtimeout=0, fsync=false

WriteConcern(String w, int wtimeout, boolean fsync, boolean j)
Creates a WriteConcern object.

WriteConcern(String w, int wtimeout, boolean fsync, boolean j, Boolean continueInsertOnError)
Creates a WriteConcern object.

Method Summary

protected WriteConcern	_instance(Object wValue, int wtimeout, boolean fsync, boolean j, boolean cont)
boolean	callGetLastError() Returns whether "getlasterror" should be called (w > 0)
boolean	continueOnErrorForInsert() Returns whether (batch) inserts will continue if an error occurs before the end
boolean	equals(Object o)
boolean	fsync() Returns whether writes wait for files to be synced to disk
BasicDBObject	getCommand() Gets the object representing the "getlasterror" command
int	getW() Gets the number of servers to write to if W is not a string value, returns -999.
String	getWString()
int	getWtimeout() Gets the write timeout (in milliseconds)
Object	getWValue() Gets the w value (either int or string)
boolean	j() Returns whether writes will await a group commit to the journal.
static WriteConcern.Majority	majorityWriteConcern(int wtimeout, boolean fsync, boolean j) Create a Majority Write Concern that requires a majority of servers to acknowledge the write.
boolean	raiseNetworkErrors() Returns whether network error may be raised (w >= 0)
String	toString()
static WriteConcern	valueOf(String name) Gets the WriteConcern constants by name: NONE, NORMAL, SAFE, FSYNC_SAFE, REPLICA_SAFE.
WriteConcern	withContinueOnErrorForInsert(boolean cont) Clones this WriteConcern with a new boolean mode for "continue inserts on error" (WriteConcerns are immutable)
WriteConcern	withFsync(boolean fsync) Clones this WriteConcern with a new boolean mode for fsync (WriteConcerns are immutable)
WriteConcern	withJ(boolean j) Clones this WriteConcern with a new "j" (WriteConcerns are immutable)
WriteConcern	withW(int w) Clones this WriteConcern with a new int mode for "w" (WriteConcerns are immutable)
WriteConcern	withW(String mode) Clones this WriteConcern with a new String mode for "w" (WriteConcerns are immutable)

Methods inherited from class java.lang.Object

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

Field Detail

NONE

public static final WriteConcern NONE

No exceptions are raised, even for network issues

NORMAL

public static final WriteConcern NORMAL

Exceptions are raised for network issues, but not server errors

SAFE

public static final WriteConcern SAFE

Exceptions are raised for network issues, and server errors; waits on a server for the write operation

MAJORITY

public static final WriteConcern MAJORITY

Exceptions are raised for network issues, and server errors; waits on a majority of servers for the write operation

FSYNC_SAFE

public static final WriteConcern FSYNC_SAFE

Exceptions are raised for network issues, and server errors; the write operation waits for the server to flush the data to disk

JOURNAL_SAFE

public static final WriteConcern JOURNAL_SAFE

Exceptions are raised for network issues, and server errors; the write operation waits for the server to group commit to the journal file on disk

REPLICAS_SAFE

public static final WriteConcern REPLICAS_SAFE

Exceptions are raised for network issues, and server errors; waits for at least 2 servers for the write operation

Constructor Detail

WriteConcern

public WriteConcern()

Default constructor keeping all options as default

WriteConcern

public WriteConcern(int w)

Calls WriteConcern(int, int, boolean) with wtimeout=0 and fsync=false

Parameters:

w - number of writes

WriteConcern

public WriteConcern(String w)

Tag based Write Concern with wtimeout=0, fsync=false, and j=false

Parameters:

w - Write Concern tag

WriteConcern

public WriteConcern(String w,
                    boolean j)

Tag based Write Concern with configgable j and wtimeout=0, fsync=false

Parameters:

w - Write Concern Tag

j - whether writes should wait for a journaling group commit

WriteConcern

public WriteConcern(int w,
                    int wtimeout)

Calls WriteConcern(int, int, boolean) with fsync=false

Parameters:

w - number of writes

wtimeout - timeout for write operation

WriteConcern

public WriteConcern(boolean fsync)

Calls WriteConcern(int, int, boolean) with w=1 and wtimeout=0

Parameters:

fsync - whether or not to fsync

WriteConcern

public WriteConcern(int w,
                    int wtimeout,
                    boolean fsync)

Creates a WriteConcern object.

Specifies the number of servers to wait for on the write operation, and exception raising behavior

w represents the number of servers:

• w=-1 None, no checking is done
• w=0 None, network socket errors raised
• w=1 Checks server for errors as well as network socket errors raised
• w>1 Checks servers (w) for errors as well as network socket errors raised

Parameters:

w - number of writes

wtimeout - timeout for write operation

fsync - whether or not to fsync

WriteConcern

public WriteConcern(int w,
                    int wtimeout,
                    boolean fsync,
                    boolean j)

Creates a WriteConcern object.

Specifies the number of servers to wait for on the write operation, and exception raising behavior

w represents the number of servers:

• w=-1 None, no checking is done
• w=0 None, network socket errors raised
• w=1 Checks server for errors as well as network socket errors raised
• w>1 Checks servers (w) for errors as well as network socket errors raised

Parameters:

w - number of writes

wtimeout - timeout for write operation

fsync - whether or not to fsync

j - whether writes should wait for a journaling group commit

WriteConcern

public WriteConcern(int w,
                    int wtimeout,
                    boolean fsync,
                    boolean j,
                    boolean continueInsertOnError)

Creates a WriteConcern object.

Specifies the number of servers to wait for on the write operation, and exception raising behavior

w represents the number of servers:

• w=-1 None, no checking is done
• w=0 None, network socket errors raised
• w=1 Checks server for errors as well as network socket errors raised
• w>1 Checks servers (w) for errors as well as network socket errors raised

Parameters:

w - number of writes

wtimeout - timeout for write operation

fsync - whether or not to fsync

j - whether writes should wait for a journaling group commit

WriteConcern

public WriteConcern(String w,
                    int wtimeout,
                    boolean fsync,
                    boolean j)

Creates a WriteConcern object.

Specifies the number of servers to wait for on the write operation, and exception raising behavior

w represents the number of servers:

• w=-1 None, no checking is done
• w=0 None, network socket errors raised
• w=1 Checks server for errors as well as network socket errors raised
• w>1 Checks servers (w) for errors as well as network socket errors raised

Parameters:

w - number of writes

wtimeout - timeout for write operation

fsync - whether or not to fsync

j - whether writes should wait for a journaling group commit

WriteConcern

public WriteConcern(String w,
                    int wtimeout,
                    boolean fsync,
                    boolean j,
                    Boolean continueInsertOnError)

Creates a WriteConcern object.

Specifies the number of servers to wait for on the write operation, and exception raising behavior

w represents the number of servers:

• w=-1 None, no checking is done
• w=0 None, network socket errors raised
• w=1 Checks server for errors as well as network socket errors raised
• w>1 Checks servers (w) for errors as well as network socket errors raised

Parameters:

w - number of writes

wtimeout - timeout for write operation

fsync - whether or not to fsync

j - whether writes should wait for a journaling group commit

Method Detail

getCommand

public BasicDBObject getCommand()

Gets the object representing the "getlasterror" command

Returns:

getW

public int getW()

Gets the number of servers to write to if W is not a string value, returns -999. You should migrate to using getWValue (returns Object) or getWString (String)

Returns:

getWString

public String getWString()

getWtimeout

public int getWtimeout()

Gets the write timeout (in milliseconds)

Returns:

fsync

public boolean fsync()

Returns whether writes wait for files to be synced to disk

Returns:

j

public boolean j()

Returns whether writes will await a group commit to the journal.

Returns:

boolean

continueOnErrorForInsert

public boolean continueOnErrorForInsert()

Returns whether (batch) inserts will continue if an error occurs before the end

Returns:

boolean

raiseNetworkErrors

public boolean raiseNetworkErrors()

Returns whether network error may be raised (w >= 0)

Returns:

callGetLastError

public boolean callGetLastError()

Returns whether "getlasterror" should be called (w > 0)

Returns:

valueOf

public static WriteConcern valueOf(String name)

Gets the WriteConcern constants by name: NONE, NORMAL, SAFE, FSYNC_SAFE, REPLICA_SAFE. (matching is done case insensitively)

Parameters:

name -

Returns:

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

getWValue

public Object getWValue()

Gets the w value (either int or string)

Returns:

withW

public WriteConcern withW(String mode)

Clones this WriteConcern with a new String mode for "w" (WriteConcerns are immutable)

Parameters:

mode -

Returns:

withW

public WriteConcern withW(int w)

Clones this WriteConcern with a new int mode for "w" (WriteConcerns are immutable)

Parameters:

mode -

w -

Returns:

withJ

public WriteConcern withJ(boolean j)

Clones this WriteConcern with a new "j" (WriteConcerns are immutable)

Parameters:

j -

Returns:

withContinueOnErrorForInsert

public WriteConcern withContinueOnErrorForInsert(boolean cont)

Clones this WriteConcern with a new boolean mode for "continue inserts on error" (WriteConcerns are immutable)

Parameters:

cont -

Returns:

withFsync

public WriteConcern withFsync(boolean fsync)

Clones this WriteConcern with a new boolean mode for fsync (WriteConcerns are immutable)

Parameters:

fsync -

Returns:

_instance

protected WriteConcern _instance(Object wValue,
                                 int wtimeout,
                                 boolean fsync,
                                 boolean j,
                                 boolean cont)

majorityWriteConcern

public static WriteConcern.Majority majorityWriteConcern(int wtimeout,
                                                         boolean fsync,
                                                         boolean j)

Create a Majority Write Concern that requires a majority of servers to acknowledge the write.

Parameters:

wtimeout - timeout for write operation

fsync - whether or not to fsync

j - whether writes should wait for a journaling group commit