These 5 parameters are going to be present, although with different prefixes, for all the workqueues to be covered. These parameters should be configured when resource consumption becomes a concern (typically during load peak times); in particular, maximum number of threads to be created, stack memory to be allocated and maximum number of request to be queued up for processing. For specific details on what each of these configuration settings do, please refer to the Artix Configuration Reference guide.
thread_pool:initial_threads
thread_pool:low_water_mark
thread_pool:high_water_mark
thread_pool:max_queue_size
thread_pool:stack_size
The default values for each of these variables are: "5", "-1", "-1", "-1", respectively. ("-1" stands for "unlimited").
For the last variable, the default is OS dependant. 0 for most operating systems (i.e. it defaults to whatever pthread_create()/CreateThread() decides. 128K for HP-UX PA-RISC, 1MB for HP-UX IA64). In a typical Artix installation, this variable is already set in the out-of-the box configuration file ($IT_PRODUCT_DIR/cxx_java/etc/domains/artix.cfg) to "1048576"; effectively making the default 1MB on all platforms.
2. Artix Bus' workqueue.
An Artix Bus always creates one workqueue for itself. This workqueue also has 5 configurable parameters:
bus:thread_pool:initial_threads
bus:thread_pool:low_water_mark
bus:thread_pool:high_water_mark
bus:thread_pool:stack_size
bus:thread_pool:max_queue_size
The default values for each of these variables are: "5", "-1", "-1", "1048576", "-1", respectively. ("-1" stands for "unlimited").
If any of these variables are not specified, configuration lookup falls back to the ORB's workqueue variables. For example, the variable "thread_pool:stack_size" set in $IT_PRODUCT_DIR/cxx_java/etc/domains/artix.cfg affects both, the Bus' and the ORB's workqueues.
3. Artix Service's workqueues.
The relationship between Services and workqueues can be categorized in three different ways:
3.1 A service can use the Bus's workqueue.
This is the default; however, the out-of-the-box configuration file $IT_PRODUCT_DIR/cxx_java/etc/domains/artix.cfg overrides it by setting the global variable
"service:owns_workqueue" to "true", making option 3.2 the effective default. Although, you can change this by either commenting the variable out or by setting it to "false".
3.2 A service can create its own workqueue.
This option is turned on by either one of the following two configuration variables:
service:SERVICE-QNAME:owns_workqueue = "true"; // specific for the service SERVICE-QNAME (namespace:local_part).
service:owns_workqueue = "true"; // affects all services in a Bus
As mentioned above in 3.1, the "service:owns_workqueue" variable is by default set to "true" in the out-of-the-box configuration file.
The parameters of the workqueue created by the service can be controlled with:
service:<SERVICE-QNAME>:thread_pool:initial_threads
service:<SERVICE-QNAME>:thread_pool:low_water_mark
service:<SERVICE-QNAME>:thread_pool:high_water_mark
service:<SERVICE-QNAME>:thread_pool:stack_size
service:<SERVICE-QNAME>:thread_pool:max_queue_size
The default values for each of these variables are: "1", "5", "25", "1048576", "-1", respectively. ("-1" stands for "unlimited").
If any of these variab./BLOCKQUOTE>
The default values for each of these variables are: "5", "-1", "-1", "-1", respectively. ("-1" stands for "unlimited").
For the last variable, the default is OS dependant. 0 for most operating systems (i.e. it defaults to whatever pthread_create()/CreateThread() decides. 128K for HP-UX PA-RISC, 1MB for HP-UX IA64). In a typical Artix installation, this variable is already set in the out-of-the box configuration file ($IT_PRODUCT_DIR/cxx_java/etc/domains/artix.cfg) to "1048576"; effectively making the default 1MB on all platforms.
3.3 Set of Services can share a named workqueue, created by the Bus specifically for them
This option is turned on by configuring either of the following:
service:<SERVICE-QNAME>:shares_workqueue = "<WORKQUEUE_NAME>"; // for individual services
service:shares_workqueue = "<WORKQUEUE_NAME>"; // for all services in a Bus
A shared named worqueue is configured with
service:<WORKQUEUE_NAME>:thread_pool:initial_threads
service:<WORKQUEUE_NAME>:thread_pool:low_water_mark
service:<WORKQUEUE_NAME>:thread_pool:high_water_mark
service:<WORKQUEUE_NAME>:thread_pool:stack_size
service:<WORKQUEUE_NAME>:thread_pool:max_queue_size
The default values for each of these variables are: "5", "-1", "-1", "1048576", "-1", respectively. ("-1" stands for "unlimited").
If any of these variables is not set, configuration look-up falls back exactly as described in 3.2
4. Considerations for Artix transports
Artix HTTP and HTTPS transports will use some threads borrowed from the bus' thread pool in order to perform transport related operations; by default, each of them will borrow 5 threads from the pool. This means that if you are using HTTP and HTTPS transports in the same Artix instance you will need to account for 10 threads to be taken from the bus' thread pool on behalf of those transports and these threads will not be available to process regular work items. Consequently, you need to make sure the ORB's and the bus' thread pools are configured to be large enough to accommodate for this.
The number of threads that is borrowed for each transport can also be configured via the following two variables:
plugins:https:pool:max_threads
plugins:http:pool:max_threads
The default value for each of these variables is: "5"
5. Configuration considerations when multiple Artix buses are created within the same process
When multiple Artix buses exist in the same process, you can configure each bus independently by ensuring that each bus gets its configuration from a unique configuration scope. This configuration scope is provided to each bus via the "-ORBname" argument passed to init() during initialization. For instance, if two Artix buses have been created and two different "-ORBname" parameters have been provided ("bus_1" and "bus_2"), you will need to add each bus' thread.ing settings under each corresponding configuration scope as shown below:
bus_1 {
thread_pool: ...
...
};
bus_2 {
thread_pool: ...
...
};
.
