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java.lang.Object | +--dd.api.DDLocateMsg
Messages sent from one machine to one or more machines
advertising the given objguid and
satisfying the given tag query.
The intended functionality of this event (outgoing) is as follows. The
message is routed toward the given guid in the network,
and at each hop the query is applied to any object
pointers associated with the given
objguid, along with the current
query_state. The query should return a result, and possibly modify
the query_state as well. The result can be one of
DDQueryResultMatch or DDQueryResultNoMatch.
A matching result indicates which object
pointers to follow, as well as
whether or not to continue routing up the tree towards the root.
A non-matching result causes the query to continue towards the root
without following any object pointers.
If the DDLocateMsg makes it way all the way to the root
without getting a positive query result, a DDLocateFailure is
returned to the original DDLocateMsg requestor.
DDLocateFailure| Field Summary | |
|---|---|
boolean |
forward
If true, DD will forward the DDLocateMsg
to any ptr location where the
query result is a
match. |
SecureHash |
guid
The queried objguid. |
int |
hopCount
Number of hops taken by the message on its way to the application. |
SecureHash |
id
A unique ID for this message, in order that a DDLocateFailure can be matched to the location request;
set to null if you do not want failure notification. |
boolean |
inbound
Whether this message is being received ( true) or sent
(false). |
static byte |
INTERMEDIATE_NONE
The underlying DHT will send the message directly to the root and will not consider intermiate nodes and ptrs. |
static byte |
INTERMEDIATE_PTRS_CACHE_ONLY
Similar to INTERMEDIATE_UPCALL_ONLY except that
intermediate ptrs will be considered
in addition to root ptrs.
|
static byte |
INTERMEDIATE_PTRS_DISK
Similar to INTERMEDIATE_PTRS_CACHE_ONLY except that
intermediate ptrs stored on disk
will be used. |
static String[] |
INTERMEDIATE_STRING
String representation of
intermediate_upcall_policy. |
static byte |
INTERMEDIATE_UPCALL_ONLY
The underlying DHT will generate an upcall event to the DD on each intermediate node in the path. |
byte |
intermediate_upcall_policy
Either the underlying DHT will send the message directly to the root and will not consider intermiate nodes and ptrs
or the underlying DHT will generate an upcall event to the DD on each
intermediate node in the path potentially considering intermediate
ptrs as well. |
boolean |
one_hop
One hop is a (possible) optimization. |
SecureHash |
peer
If inbound, the sender; undefined otherwise. |
DDQuery |
query
The DDQuery.query(ostore.util.SecureHash, bamboo.vivaldi.VirtualCoordinate, ostore.util.SecureHash, dd.host.api.HostInfo, dd.api.DDTag, dd.api.DDQueryState) to execute on each object
pointer. |
DDQueryState |
query_state
The state to pass the
DDQuery.query(ostore.util.SecureHash, bamboo.vivaldi.VirtualCoordinate, ostore.util.SecureHash, dd.host.api.HostInfo, dd.api.DDTag, dd.api.DDQueryState) executed on each object
pointer. |
boolean |
recursive_route
If true recursive route between src and root;
otherwise, iterative route. |
int |
TTL
Number of hops this message should take before delivering payload. |
bamboo.vivaldi.VirtualCoordinate |
vc
The VirtualCoordinate to use when
resolving ptr locations.
|
static byte |
VC_NONE
Do not use any VirtualCoordinate
when resolving ptr locations. |
byte |
vc_policy
The VirtualCoordinate to use
when resolving ptr locations.
|
static byte |
VC_ROOT
Use root VirtualCoordinate
when resolving ptr locations. |
static byte |
VC_SRC
Use src VirtualCoordinate
when resolving ptr locations. |
static String[] |
VC_STRING
String representation of vc_policy. |
static byte |
VC_SUPPLIED
Use the supplied VirtualCoordinate
when resolving ptr locations. |
| Constructor Summary | |
|---|---|
DDLocateMsg()
Empty constructor. |
|
DDLocateMsg(SecureHash guid,
DDQuery query,
DDQueryState query_state,
SecureHash id,
boolean forward,
boolean recursive_route,
boolean one_hop,
byte intermediate_upcall_policy,
byte vc_policy,
bamboo.vivaldi.VirtualCoordinate vc)
Constructor: Creates a new DDLocateMsg.
|
|
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Methods inherited from interface ostore.util.QuickSerializable |
|---|
serialize |
| Field Detail |
public static final byte INTERMEDIATE_NONE
ptrs. By not using intermediate upcalls
the values for hopCount and TTL will be undefined and
intermediate ptrs will not be
considered.
public static final byte INTERMEDIATE_UPCALL_ONLY
hopCount and TTL to be accounted for correctly.
But intermediate ptrs will not be
considered, only root ptrs will be used.
public static final byte INTERMEDIATE_PTRS_CACHE_ONLY
INTERMEDIATE_UPCALL_ONLY except that
intermediate ptrs will be considered
in addition to root ptrs.
But only intermediate ptrs that
are immediately available in cache will be used; that is,
the disk is not used for intermediate
ptrs.
public static final byte INTERMEDIATE_PTRS_DISK
INTERMEDIATE_PTRS_CACHE_ONLY except that
intermediate ptrs stored on disk
will be used.
public static final String[] INTERMEDIATE_STRING
String representation of
intermediate_upcall_policy.
public static final byte VC_NONE
VirtualCoordinate
when resolving ptr locations.
public static final byte VC_SRC
VirtualCoordinate
when resolving ptr locations.
public static final byte VC_ROOT
VirtualCoordinate
when resolving ptr locations.
public static final byte VC_SUPPLIED
VirtualCoordinate
when resolving ptr locations.
public static final String[] VC_STRING
String representation of vc_policy.
public SecureHash peer
inbound, the sender; undefined otherwise.
public boolean inbound
true) or sent
(false).
public SecureHash guid
objguid.
public DDQuery query
DDQuery.query(ostore.util.SecureHash, bamboo.vivaldi.VirtualCoordinate, ostore.util.SecureHash, dd.host.api.HostInfo, dd.api.DDTag, dd.api.DDQueryState) to execute on each object
pointer. See the class comments, above.
public DDQueryState query_state
state to pass the
DDQuery.query(ostore.util.SecureHash, bamboo.vivaldi.VirtualCoordinate, ostore.util.SecureHash, dd.host.api.HostInfo, dd.api.DDTag, dd.api.DDQueryState) executed on each object
pointer. See the class comments, above.
public boolean forward
true, DD will forward the DDLocateMsg
to any ptr location where the
query result is a
match. Otherwise,
DDLocateMsg will be returned back to the original sender
when either the query result
match states to
DDQueryResultMatch.stop() or the DDLocateMsg
reaches the root with and
DDQueryResultMatch.stop()==falseforward==true any recipient of the
DDLocateMsg will not receive the
state, but when forward==false
the original sender will receive the
state.
public boolean recursive_route
true recursive route between src and root;
otherwise, iterative route. Recursive route
means that each node in the path forwards the message to the next
node. The recursive route continues until the message reaches the root.
Whereas, iterative route means each node in the path sends
back to the source the next node and the source itself sends the
message to the next node. The iterative route continues until the
message reaches the root. In either case, when the message reaches
the root, the root will forward the message to matching
ptr locations.
public boolean one_hop
host db,
it is possible to look up the root entry in the the
db. If a root exists,
then forward the message directly to the root in one hop.
Note one_hop=T and an entry exists, intermediate nodes will
not be used.
public byte intermediate_upcall_policy
ptrs
or the underlying DHT will generate an upcall event to the DD on each
intermediate node in the path potentially considering intermediate
ptrs as well. The options are:
INTERMEDIATE_NONE: send the message directly to the root.
INTERMEDIATE_UPCALL_ONLY: upcall on each intermediate node
in the path. Only consider hopCount and TTL, but
not
INTERMEDIATE_PTRS_CACHE_ONLY: Similar to
INTERMEDIATE_UPCALL_ONLY except that intermediate
ptrs will be considered in addition
to root ptrs. But only intermediate
ptrs that are immediately available
in cache will be used; that is, the disk is not used for
intermediate ptrs.
INTERMEDIATE_PTRS_DISK: Similar to
INTERMEDIATE_PTRS_CACHE_ONLY except that intermediate
ptrs stored on disk
will be used.
public byte vc_policy
VirtualCoordinate to use
when resolving ptr locations.
Valid setting are: VC_NONE, VC_SRC,
VC_ROOT, or VC_SUPPLIED.
The vc parameter is ignored and set to the specified policy;
unless, VC_SUPPLIED is the policy (in that case the
vc parameter is used to resolve
ptr locations.
public bamboo.vivaldi.VirtualCoordinate vc
VirtualCoordinate to use when
resolving ptr locations.
This parameter is only used when the
vc_policy=VC_SUPPLIEDvc parameter is ignored.
public int hopCount
public int TTL
public SecureHash id
DDLocateFailure can be matched to the location request;
set to null if you do not want failure notification.
| Constructor Detail |
public DDLocateMsg(SecureHash guid,
DDQuery query,
DDQueryState query_state,
SecureHash id,
boolean forward,
boolean recursive_route,
boolean one_hop,
byte intermediate_upcall_policy,
byte vc_policy,
bamboo.vivaldi.VirtualCoordinate vc)
DDLocateMsg.
Construct with the given guid, query, and state; will return a
DDLocateFailure with the same id if
the location fails. Set id to null
if a failure response is not needed. Use for new outbound messages.
An example parameter setting for sending a message to the closest replica or service to the src:
forward=Trecursive_route=Tone_hop=Fintermediate_upcall_policy=INTERMEDIATE_PTRS_DISKvc_policy=VC_SRCvc=nullFor finding the closest replica or service to the src (without sending the replica or service a message):
forward=Frecursive_route=Tone_hop=Fintermediate_upcall_policy=INTERMEDIATE_PTRS_DISKvc_policy=VC_SRCvc=nullAnother example parameter setting for sending a message to the closest m-of-n replica or service instances where m is greater than the number that is likely to be found on intermediate nodes. That is, just route directly to the root as quickly as possible.
forward=Trecursive_route=Tone_hop=Tintermediate_upcall_policy=INTERMEDIATE_NONEvc_policy=VC_NONEvc=nullAgain for finding the closest m-of-n replica or service instances:
forward=Frecursive_route=Tone_hop=Tintermediate_upcall_policy=INTERMEDIATE_NONEvc_policy=VC_NONEvc=null
guid - Object guid attempt to resolve.query - DDQuery.query(ostore.util.SecureHash, bamboo.vivaldi.VirtualCoordinate, ostore.util.SecureHash, dd.host.api.HostInfo, dd.api.DDTag, dd.api.DDQueryState) to execute on each object
PublishInfo.query_state - The state to pass the
DDQuery.query(ostore.util.SecureHash, bamboo.vivaldi.VirtualCoordinate, ostore.util.SecureHash, dd.host.api.HostInfo, dd.api.DDTag, dd.api.DDQueryState) executed on each object
pointer.id - A unique ID for this message, in order that a
DDLocateFailure can be matched to the location
request; set to null if you do not want failure
notification.forward - If true, DD will forward the
DDLocateMsg to any ptr
location where the query result
is a match. Otherwise,
DDLocateMsg will be returned back to the original sender
when either the query result
match states to
DDQueryResultMatch.stop() or the DDLocateMsg
reaches the root with and
DDQueryResultMatch.stop()==falserecursive_route - If true recursive route
between src and root; otherwise, iterative route. See
recursive_route for more details.one_hop - One hop is a (possible) optimization. Since the DD
maintains a host
db, it is possible to look up
the root entry in the the
db. If a root
exists, then forward the message directly to the root
in one hop. Note one_hop=T and an entry exists,
intermediate nodes will not be used.intermediate_upcall_policy - Either the underlying DHT will send the
message directly to the root and will not consider intermiate nodes
and ptrs or the underlying DHT will
generate an upcall event to the DD on each intermediate node in the
path potentially considering intermediate
ptrs as well.
See intermediate_upcall_policy for more details.vc_policy - The VirtualCoordinate to use
when resolving ptr locations.
Valid setting are: VC_NONE, VC_SRC,
VC_ROOT, or VC_SUPPLIED.vc - This parameter is only used when the
vc_policy=VC_SUPPLIEDvc parameter is ignored.public DDLocateMsg()
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