C Topic Configuration Element Reference
Note:
Coherence XML configuration files are validated at runtime using the corresponding XML schemas. It is important that any custom configuration files conform to the schema, because something as simple as having elements in the wrong order will cause validation to fail. As validation errors produced by XML schema validators can be difficult to understand, we recommend that custom configuration files are edited in a development environment capable of validating the XML against the schema as it is being written. This can save a lot of time compared to debugging validation errors at runtime.
This appendix includes the following sections:
page-size
Used in: paged-topic-scheme
Description
The page-size element specifies the target page size. The default value is 1MB.
Parent topic: Topic Configuration Element Reference
paged-topic-scheme
Used in: caching-schemes
Description
The paged-topic-scheme defines topics where the storage
for values and metadata is partitioned across cluster nodes.
Elements
Table C-1 describes the subelements of the paged-topic-scheme element.
Table C-1 paged-topic-scheme Subelements
| Element | Required/Optional | Description |
|---|---|---|
|
< |
Optional |
Specifies the scheme's name. The name must be unique within a configuration file. |
|
< |
Optional |
Specifies the name of another scheme to inherit from. See Using Scheme Inheritance |
|
< |
Optional |
Specifies the scope name for this configuration. The scope name is added (as a prefix) to all services generated by a cache factory. The name is used to isolate services when using multiple cache factories; thus, avoiding unintended joining of services with similar names from different configurations. |
|
< |
Optional |
Specifies a name for the distributed cache service
instance that manages the topic that is created from this
scheme. The distributed cache service definition is defined
within the |
|
< |
Optional |
Specifies the priority for the service thread. Legal
values are from 1 to 10 where 10 is the highest priority. The
default value is the |
|
< |
Optional |
Specifies the priority for the event dispatcher
thread for each service. Legal values are from 1 to 10 where 10
is the highest priority. The default value is the
|
|
< |
Optional |
Specifies either: the class configuration information
for a You cannot change this element during a rolling restart. For example, you cannot change from java to pof serialization or the serializer class. |
|
< |
Optional |
Specifies the transport protocol used by this
service for reliable point-to-point communication. Specifying a
value results in the use of a service-specific transport
instance rather then the shared transport instance that is
defined by the <
unicast-listener> element. A service-specific transport instance
can result in higher performance but at the cost of increased
resource consumption and should be used sparingly for select,
high priority services. In general, a shared transport instance
uses less resource consumption than service-specific transport
instances. Valid values are:
The default value is the
You cannot change this element from TLS to non-TLS during a
rolling restart. You are however able to change between
|
|
< |
Optional |
Specifies whether or not backup updates should be compressed in
delta form or sent whole. A delta update represents the parts of
a backup entry that must be changed in order to synchronize it
with the primary version of the entry. Deltas are created and
applied using a compressor. The default value is the
compressor value specified in the
tangosol-coherence.xml descriptor. See the
compressor parameter in DistributedCache Service Parameters. Valid values
are:
|
|
< |
Optional |
Specifies the maximum number of daemon threads. Usage of daemon
threads varies for different service types. If zero or negative,
the service does not use daemon threads and all relevant tasks
are performed on the service thread. Furthermore, if negative,
tasks are performed on the caller's thread where possible. Valid
values are integers greater or equal to the value of the
|
|
< |
Optional |
Specifies the minimum number of daemon threads. Usage of daemon
threads varies for different service types. If zero or negative,
the service does not use daemon threads and all relevant tasks
are performed on the service thread. Furthermore, if negative,
tasks are performed on the caller's thread where possible. Valid
values are integers less than or equal to the value of the
|
|
< |
Optional |
Specifies the priority for the worker threads. Legal values are
from 1 to 10 where 10 is the highest priority. The default value
is the |
|
< |
Optional |
Specifies whether a cluster node contributes storage to the
cluster, that is, maintain partitions. When disabled the node is
considered a cache client. Legal values are
|
|
< |
Optional |
Specifies the number of distributed cache partitions. Each storage-enabled cluster member that is running the distributed cache service manages a balanced number of partitions. Valid values are positive integers between 1 and 32767 and should
be a prime number. A list of primes can be found at You cannot change this element during a rolling restart.This may
appear to work but you will receive a message like the following
indicating the change has been ignored: |
|
< |
Optional |
Specifies the threshold for the primary buckets distribution in
kilobytes. When a new node joins the partitioned cache service
or when a member of the service leaves, the remaining nodes
perform a task of bucket ownership re-distribution. During this
process, the existing data gets re-balanced along with the
ownership information. This parameter indicates a preferred
message size for data transfer communications. Setting this
value lower makes the distribution process take longer, but
reduces network bandwidth utilization during this activity.
Legal values are integers greater then zero. The default value
is the |
|
< |
Optional |
Specifies the number of members of the paged topic service that
hold the backup data for each unit of storage in the topic. A
value of 0 means that for abnormal termination, some portion of
the data in the topic is lost. The default value is the
You cannot change this element during a rolling restart.This may
appear to work but you will receive a message like the following
indicating the change has been ignored: |
|
|
Optional |
Specifies the strategy that is used by a partitioned service to
manage partition distribution. The default value is the
partition-assignment-strategy value
specified in the tangosol-coherence.xml
descriptor. See the
partition-assignment-strategy parameter in
DistributedCache Service Parameters
You cannot change this element during a rolling restart. |
|
< |
Optional |
Specifies the guardian timeout value to use for guarding the
service and any dependent threads. If the element is not
specified for a given service, the default guardian timeout (as
specified by the The value of this element must be in the following format:
|
|
< |
Optional |
Specifies the action to take when an abnormally behaving service thread cannot be terminated gracefully by the service guardian. Legal values are:
|
|
< |
Optional |
Specifies the configuration information for a class that
implements the The |
|
< |
Optional |
This enum type specifies the storage scheme used to hold topic values and metadata. Valid values are |
|
< |
Optional |
Specifies whether or not the topic values and metadata should be
persisted using a persistence environment. Valid values are
|
|
< |
Optional |
Specifies the persistence-related configuration for a partitioned
cache service. If this element exists and no
|
|
< |
Optional |
Specifies a reference to a storage access authorizer that is defined in an operational configuration file. The storage access authorizer is used by a partitioned cache to authorize access to the underlying cache data. If configured, all read and write access to the data in the topic storage will be validated and/or audited by the configured authorizer. The following example references a storage access authorizer
definition with the
id attribute
auditing.See storage-authorizer. |
|
< |
Optional |
Specifies quorum policy settings for the partitioned cache service. |
|
< |
Optional |
The |
|
< |
Optional |
Specifies any number of event interceptors that process events for all caches of a specific distributed service. |
|
< |
Optional |
The page-size element specifies the target page size. |
|
< |
Optional |
Specifies the amount of time since a value was published to a topic that it is available to be received by subscriber(s). An expired value is no longer accessible. The value of this element must be in the following
format:
where the first non-digits (from left to right) indicate the unit
of time duration:
If the value does not contain a unit, a unit of seconds is
assumed. A value of zero implies no expiry. The default value is
0.
Note: The expiry delay parameter (cExpiryMillis) is defined as an
integer and is expressed in milliseconds. Therefore, the
maximum amount of time can never exceed
Integer.MAX_VALUE (2147483647)
milliseconds or approximately 24 days.
|
|
< |
Optional |
Specifies the size limit of the topic. The value represents the maximum number of bytes for the unprocessed values retained by the topic. Dependent on how the publisher is configured and its threads try-with-resource state, the next send could be throttled by flow control, fail on full or proceed to send values to the topic. Valid values are positive integers and 0. The value of this element must be in the following format: (\d)+[K|k|M|m|G|g|T|t]?[B|b]? where the first non-digit (from left to right) indicates the factor with which the preceding decimal value should be multiplied:
The default value is |
Parent topic: Topic Configuration Element Reference
subscriber-group
Used in: subscriber-groups
Description
The subscriber-group element defines a durable
subscription group for a topic-mapping.
Elements
Table C-2 describes the subelements of the subscriber-group element.
Table C-2 subscriber-group Subelements
| Element | Required/Optional | Description |
|---|---|---|
|
< |
Required |
Subscriber group name. |
Parent topic: Topic Configuration Element Reference
subscriber-groups
Used in: topic-mapping
Description
The subscriber-groups element enables defining one or more durable
subscription group(s) in a topic-mapping. These groups will be created along with
the topic and as such are ensured to exist before any data is published to the
topic.
Elements
Table C-3 describes the subelements of the subscriber-groups element.
Table C-3 subscriber-groups Subelements
| Element | Required/Optional | Description |
|---|---|---|
|
< |
Required |
One or more subscriber-group elements that define durable subscription group(s) for the topic-mapping. |
Parent topic: Topic Configuration Element Reference
topic-mapping
Used in: topic-scheme-mapping
Description
Each topic-mapping element specifies the
paged-topic-scheme what are to be used for a given topic name
or topic name pattern used by an application.
Elements
topic-mapping element.
Table C-4 topic-mapping Subelements
| Element | Required/Optional | Description |
|---|---|---|
|
< |
Required |
Specifies a topic name or name pattern. The name
is unique within topics created by a cache factory. The
slash (
/) and colon (:)
are reserved characters and cannot be used in cache names.
The following topic name patterns are supported:
If a topic name can be matched to multiple topic mappings, then exact matches are selected over wildcard matches. If no exact match is specified, then the last matching wildcard pattern (based on the order in which they are defined in the file) is selected. |
|
< |
Required |
Contains the topic scheme name. The name is
unique within a configuration file. Topic schemes are
configured in |
|
< |
Optional |
Specifies the fully-qualified name of the Java
class for |
|
< |
Optional |
The |
|
< |
Optional |
Allows specifying replaceable topic scheme
parameters. During topic scheme parsing, any occurrence of
any replaceable parameter in format
param-name is replaced with the
corresponding parameter value. Consider the following topic
mapping
example:Any occurrence of the literal {page-size} will be replaced with the value of 10MB. |
Parent topic: Topic Configuration Element Reference
topic-scheme-mapping
Used in: cache-config
Description
Defines mappings between topic names, or name patterns, and a paged-topic-scheme.
Elements
topic-scheme-mapping element.
Table C-5 topic-scheme-mapping Subelements
| Element | Required/Optional | Description |
|---|---|---|
|
< |
Optional |
The topic-mapping element contains a single binding between a topic name and a topic scheme this topic will use. |
Parent topic: Topic Configuration Element Reference
topic-storage-type
Used in: paged-topic-scheme
Description
This enum type specifies the storage scheme used to hold topic values and metadata.
Valid values are on-heap, flashjournal or
ramjournal. Default value is on-heap.
Parent topic: Topic Configuration Element Reference