[JBoss AS7 Development] - Format of a Detyped Operation Response
by Brian Stansberry
Brian Stansberry [http://community.jboss.org/people/brian.stansberry] modified the document:
"Format of a Detyped Operation Response"
To view the document, visit: http://community.jboss.org/docs/DOC-16354
--------------------------------------------------------------
+*Note: this document is a draft meant to spark discussion, and its content may undergo significant change*+
The basic method a user of the AS 7 programmatic managment API would use is very simple:
ModelNode execute(ModelNode operation) throws CancellationException, IOException;
where the return value is the detyped representation of the response, and operation is the detyped representation of the operating being invoked.
The purpose of this article is to document the structure of the return value.
For the format of the request, see this page (http://community.jboss.org/docs/DOC-16336).
See http://community.jboss.org/docs/DOC-16317 this page for a more in depth example of using the native management API.
h3. Simple Responses
Simple responses are provided by the following types of operations:
* Non-composite operations that target a single server. (See below for more on composite operations).
* Non-composite operations that target a DomainController or HostController and don't require the responder to apply the operation on multiple servers and aggregate their results (e.g. a simple read of a domain configuration property.)
The response will always include a simple boolean outcome field, with one of three possible values:
* success -- the operation executed successfully
* failed -- the operation failed
* cancelled -- the execution of the operation was cancelled. (This would be an unusual outcome for a simple operation which would generally very rapidly reach a point in its execution where it couldn't be cancelled.)
The other fields in the response will depend on whether the operation was sucessful.
The response for a failed operation:
{
"outcome" => "failed",
"failure-description" => "[DOM-1234] Some failure message"
}
A response for a successful operation will include an additional field:
* result -- the return value, or undefined for void operations or those that return null
A non-void result:
{
"outcome" => "success",
"result" => {
"name" => "Brian",
"age" => 22
}
}
A void result with a compensating operation:
{
"outcome" => "success",
"result" => undefined
}
The response for a cancelled operation has no other fields:
{
"outcome" => "cancelled"
}
h3.
h3. Basic Composite Operation Responses
A composite operation is one that incorporates more than one simple operation in a list and executes them atomically. See the "Composite Operations" section http://community.jboss.org/docs/DOC-16336 here for more information.
Basic composite responses are provided by the following types of operations:
* Composite operations that target a single server.
* Composite operations that target a DomainController or HostController and don't require the responder to apply the operation on multiple servers and aggregate their results (e.g. a list of simple reads of domain configuration properties.)
The high level format of a basic composite operation response is largely the same as that of a simple operation response, although there is an important semantic difference. For a composite operation, the meaning of the outcome flag is controlled by the value of the operation request's rollback-on-runtime-failure header field. If that field was false (default is true), the outcome flag will be success if *any* of the composite operation's steps was successful.
What's distinctive about a composite operation response is the result field. First, even if the operation was not successful, the result field will usually be present. (It won't be present if there was some sort of immediate failure that prevented the responder from even attempting to execute the individual operations.) Second, the content of the result field will be a list. Each element in the list will record the result of the corresponding element in the steps field of the composite operation request. So each individual operation in the composite operation will have its result recorded.
The individual operation results will have the same basic format as the simple operation results described above. However, there are some differences from the simple operation case when the individual operation's outcome flag is failed. These relate to the fact in a composite operation, individual operations can be rolled back or not even attempted.
If an individual operation was not even attempted (because the overall operation was cancelled or, more likely, a prior operation failed):
{
"outcome" => "cancelled"
}
An individual operation that failed and was rolled back:
{
"outcome" => "failed",
"failure-description" => "[DOM-1234] Some failure message",
"rolled-back" => true
}
An individual operation that itself succeeded but was rolled back due to failure of another operation:
{
"outcome" => "failed",
"result" => {
"name" => "Brian",
"age" => 22
},
"rolled-back" => true
}
An operation where the attempt at rollback was unsuccessful:
{
"outcome" => "failed",
"failure-description" => "[DOM-1234] Some failure message",
"rolled-back" => false,
"rollback-failure-description" => "[DOM-9876] Some other failure message"
}
Here's an example of the response for a successful 2 step composite operation:
{
"outcome" => "success",
"result" => [
{
"outcome" => "success",
"result" => {
"name" => "Brian",
"age" => 22
}
},
{
"outcome" => "success",
"result" => undefined
}
]
}
And for a failed 3 step composite operation, where the first step succeeded and the second failed, triggering cancellation of the 3rd and rollback of the others:
{
"outcome" => "failed",
"failure-description" => "[DOM-9999] Composite operation failed; see individual operation results for details",
"result" => [
{
"outcome" => "failed",
"result" => {
"name" => "Brian",
"age" => 22
},
"rolled-back" => true
},
{
"outcome" => "failed",
"failure-description" => "[DOM-1234] Some failure message",
"rolled-back" => true
},
{
"outcome" => "cancelled"
}
]
}
h3. Multi-Server Responses
Multi-server responses are provided by operations that target a DomainController or HostController and require the responder to apply the operation on multiple servers and aggregate their results (e.g. nearly all domain or host configuration updates.)
Multi-server operations are executed in several stages.
First, the operation may need to be applied against the authoritative configuration model maintained by the DomainController (for domain.xml confgurations) or a HostController (for a host.xml configuration). If there is a failure at this stage, the operation is automatically rolled back, with a response like this:
{
"outcome" => "failed",
"domain-failure-description" => "[DOM-3333] Failed to apply X to the domain model"
}
if the operation was addressed to the domain model, or like this:
{
"outcome" => "failed",
"host-failure-description" => "[DOM-3334] Failed to apply Y to the host model"
}
if the operation was addressed to a host model.
If the operation was addressed to the domain model, in the next stage the DomainController will ask each HostController to apply it to its local copy of the domain model. If any HostController fails to do so, the DomainController will tell all HostControllers to revert the change, and it will revert the change locally as well. The response to the client will look like this:
{
"outcome" => "failed",
"host-failure-descriptions" => {
"hostA" => "[DOM-3333] Failed to apply to the domain model",
"hostB" => "[DOM-3333] Failed to apply to the domain model"
}
}
If the preceding stages succeed, the operation will be pushed to all affected servers. If the operation is successful on all servers, the response will look like this (this operation has a void response, hence the result for each server is undefined):
{
"outcome" => "success",
"server-groups" => {
"groupA" => {
"serverA-1" => {
"host" => "host1",
"response" => {
"outcome" => "success",
"result" => undefined
}
},
"serverA-2" => {
"host" => "host2",
"response" => {
"outcome" => "success",
"result" => undefined
}
}
},
"groupB" => {
"serverB-1" => {
"host" => "host1",
"response" => {
"outcome" => "success",
"result" => undefined
}
},
"serverB-2" => {
"host" => "host2",
"response" => {
"outcome" => "success",
"result" => undefined
}
}
}
}
}
The operation need not succeed on all servers in order to get an "outcome" => "success" result. All that is required is that it succeed on at least one server without the rollback policies in the rollout plan triggering a rollback on that server. (+TODO: consider something like "outcome" => "partial" for this case, and for partially successful composite operations.+) An example response in such a situation would look like this:
{
"outcome" => "success",
"server-groups" => {
"groupA" => {
"serverA-1" => {
"host" => "host1",
"response" => {
"outcome" => "success",
"result" => undefined
}
},
"serverA-2" => {
"host" => "host2",
"response" => {
"outcome" => "success",
"result" => undefined
}
}
},
"groupB" => {
"serverB-1" => {
"host" => "host1",
"response" => {
"outcome" => "success",
"result" => undefined,
"rolled-back" => true
}
},
"serverB-2" => {
"host" => "host2",
"response" => {
"outcome" => "success",
"result" => undefined,
"rolled-back" => true
}
},
"serverB-3" => {
"host" => "host3",
"response" => {
"outcome" => "failed",
"failure-description" => "[DOM-4556] Something didn't work right",
"rolled-back" => true
}
}
}
}
}
Finally, if the operation fails or is rolled back on all servers, an example response would look like this:
{
"outcome" => "failed",
"server-groups" => {
"groupA" => {
"serverA-1" => {
"host" => "host1",
"response" => {
"outcome" => "success",
"result" => undefined
}
},
"serverA-2" => {
"host" => "host2",
"response" => {
"outcome" => "success",
"result" => undefined
}
}
},
"groupB" => {
"serverB-1" => {
"host" => "host1",
"response" => {
"outcome" => "failed",
"result" => undefined,
"rolled-back" => true
}
},
"serverB-2" => {
"host" => "host2",
"response" => {
"outcome" => "failed",
"result" => undefined,
"rolled-back" => true
}
},
"serverB-3" => {
"host" => "host3",
"response" => {
"outcome" => "failed",
"failure-description" => "[DOM-4556] Something didn't work right",
"rolled-back" => true
}
}
}
}
}
TODO: discuss some nuances related to multi-server composite operations, particularly the fact that different items in the composite may execute on different sets of servers, or only on the DC or the HC.
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[JBoss Web Development] - cmd.exe processes stranded after JBoss 5.1 service shutdown Windows 7
by Chris Davis
Chris Davis [http://community.jboss.org/people/cdavis999] created the discussion
"cmd.exe processes stranded after JBoss 5.1 service shutdown Windows 7"
To view the discussion, visit: http://community.jboss.org/message/607072#607072
--------------------------------------------------------------
I'm running JBoss EAP 5.1 as a service on Windows 7 (32-bit). I used service.bat to install/uninstall the service. I use the Windows Control Panel Services dialog to start and stop the service. JBoss starts up cleanly and JBoss itself shuts down cleanly when I stop the service (as reported by the shutdown.log). The jbosssvc.exe process and the java.exe process also disappear from Task Manager. However, Task Manager continues to show the two cmd.exe processes presumably spawned by jbosssvc.exe, for example:
Image Name PID User Name Command Line
cmd.exe 7148 SYSTEM C:\Windows\system32\cmd.exe /E:ON /S /C "SET JSERVICE_PPID=6344&&SET JSERVICE_NAME=JBEAP5SVC&&CALL service.bat start"
cmd.exe 8322 SYSTEM C:\Windows\system32\cmd.exe /E:ON /S /C "SET JSERVICE_PPID=6344&&SET JSERVICE_NAME=JBEAP5SVC&&CALL service.bat stop"
These processes have to be manually killed. Shouldn't jbosssvc.exe be able to shut these two processes down automatically? The PPID parameter in the lines above is the same as the PID for jbosssvc.exe in Task Manager. I had to tweak my bat files to match my file system paths, so I'm attaching them, along with my run.log and shutdown.log.
For reference: while the JBoss service is running, Task Manager displays these lines (before I stop the service):
Image Name PID User Name Command Line
cmd.exe 7148 SYSTEM C:\Windows\system32\cmd.exe /E:ON /S /C "SET JSERVICE_PPID=6344&&SET JSERVICE_NAME=JBEAP5SVC&&CALL service.bat start"
java.exe 3492 SYSTEM "C:\Program Files\Java\jdk1.6.0_22\bin\java" Xms512m Xmx1024m XX:PermSize=512m XX:MaxPermSize=512m Xrs Dorg.jboss.resolver.warning=true -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Dsun.lang.ClassLoader.allowArraySyntax=true
jbosssvc.exe 6344 SYSTEM "C:\JBoss510\native32\sbin\jbosssvc.exe" r JBEAP5SVC
Any help is greatly appreciated!
Chris
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12 years, 11 months
[JBoss AS7 Development] - Format of a Detyped Operation Request
by Brian Stansberry
Brian Stansberry [http://community.jboss.org/people/brian.stansberry] modified the document:
"Format of a Detyped Operation Request"
To view the document, visit: http://community.jboss.org/docs/DOC-16336
--------------------------------------------------------------
The basic method a user of the AS 7 programmatic managment API would use it very simple:
ModelNode execute(ModelNode operation) throws CancellationException, IOException;
where the return value is the detyped representation of the response, and operation is the detyped representation of the operating being invoked.
The purpose of this article is to document the structure of operation.
See http://community.jboss.org/docs/DOC-16354 this page for a discussion of the format of the response.
See http://community.jboss.org/docs/DOC-16317 this page for a more in depth example of using the native management API.
h3. Simple Operations
A text representation of simple operation would look like this:
{
"operation" => "write-core-threads",
"address" => [
("profile" => "production"),
("subsystem" => "threads"),
("bounded-queue-thread-pool" => "pool1")
],
"count" => 0,
"per-cpu" => 20
}
Java code to produce that output would be:
ModelNode op = new ModelNode();
op.get("operation").set("write-core-threads");
ModelNode addr = op.get("address");
addr.add("profile", "production");
addr.add("subsystem", "threads");
addr.add("bounded-queue-thread-pool", "pool1");
op.get("count").set(0);
op.get("per-cpu").set(20);
System.out.println(op);
The order in which the outermost elements appear in the request is not relevant. The required elements are:
* operation -- String -- The name of the operation being invoked.
* address -- the address of the managed resource against which the request should be executed. If not set, the address is the root resource. The address is an +ordered+ list of key-value pairs describing where the resource resides in the overall management resource tree. Management resources are organized in a tree, so the order in which elements in the address occur is important.
The other key/value pairs are parameter names and their values. The names and values should match what is specified in the operation's http://community.jboss.org/docs/DOC-16317 description.
Parameters may have any name, except for operation, address and operation-headers.
h3. Operation Headers
(Note: this information is correct for releases after 7.0.0.Beta2, following completion of JBAS-9112. Prior to that, the headers were at the same level as operation and address.)
Besides the special operation and address values discussed above, operation requests can also include special "header" values that help control how the operation executes. These headers are created under the special reserved word operation-headers:
ModelNode op = new ModelNode();
op.get("operation").set("write-core-threads");
ModelNode addr = op.get("address");
addr.add("base", "domain");
addr.add("profile", "production");
addr.add("subsystem", "threads");
addr.add("bounded-queue-thread-pool", "pool1");
op.get("count").set(0);
op.get("per-cpu").set(20);
op.get("operation-headers", "rollback-on-runtime-failure").set(false);
System.out.println(op);
This produces:
{
"operation" => "write-core-threads",
"address" => [
("profile" => "production"),
("subsystem" => "threads"),
("bounded-queue-thread-pool" => "pool1")
],
"count" => 0,
"per-cpu" => 20,
"operation-headers" => {
"rollback-on-runtime-failure => false
}
}
The following operation headers are supported:
* rollback-on-runtime-failure -- boolean, optional, defaults to true. Whether an operation that successfully updates the persistent configuration model should be reverted if it fails to apply to the runtime. Operations that affect the persistent configuration are applied in two stages -- first to the configuration model and then to the actual running services. If there is an error applying to the configuration model the operation will be aborted with no configuration change and no change to running services will be attempted. However, operations are allowed to changed the configuration model even if there is a failure to apply the change to the running services -- if and only if this rollback-on-runtime-failure header is set to false. So, this header only deals with what happens if there is a problem applying an operation to the running state of a server (e.g. actually increasing the size of a runtime thread pool.)
* rollout-plan -- only relevant to requests made to a Domain Controller or Host Controller. See "Operations with a Rollout Plan" for details.
h3. Composite Operations
The root resource managed by a (Domain|Host|Server)Controller will expose an operation named "composite". This operation executes a list of other operations as an atomic unit*. The structure of the request for the "composite" operations has the same fundamental structure as a simple operation (operation name, address, params as key value pairs.
+* See the discussion below of the rollback-on-runtime-failure operation header for how the atomicity requirement can be relaxed.+
{
"operation" => "composite",
"address" => [],
"steps" => [
{
"operation" => "write-core-threads",
"address" => [
("profile" => "production"),
("subsystem" => "threads"),
("bounded-queue-thread-pool" => "pool1")
],
"count" => 0,
"per-cpu" => 20
},
{
"operation" => "write-core-threads",
"address" => [
("profile" => "production"),
("subsystem" => "threads"),
("bounded-queue-thread-pool" => "pool2")
],
"count" => 5,
"per-cpu" => 10
}
],
"operation-headers" => {
"rollback-on-runtime-failure => false
}
}
The "composite" operation takes a single parameter:
* steps -- a list, where each item in the list has the same structure as a simple operation request. In the example above each of the two steps is modifying the thread pool configuration for a different pool. There need not be any particular relationship between the steps. Note that the rollback-on-runtime-failure and rollout-plan operation headers are not supported for the individual steps in a composite operation.
The rollback-on-runtime-failure operation header discussed above has a particular meaning when applied to a composite operation, controlling whether steps that successfully execute should be reverted if other steps fail at runtime. Note that if any steps modify the persistent configuration, and any of those steps fail, all steps will be reverted. Partial/incomplete changes to the persistent configuration are not allowed.
h3. Operations with a Rollout Plan
Operations targetted at domain or host level resources can potentially impact multiple servers. Such operations can include a "rollout plan" detailing the sequence in which the operation should be applied to servers as well as policies for detailing whether the operation should be reverted if it fails to execute successfully on some servers.
If the operation includes a rollout plan, the structure is as follows:
{
"operation" => "write-core-threads",
"address" => [
("profile" => "production"),
("subsystem" => "threads"),
("bounded-queue-thread-pool" => "pool1")
],
"count" => 0,
"per-cpu" => 20,
"operation-headers" => {
"rollout-plan" => {
"in-series" => [
{
"concurrent-groups" => {
"groupA" => {
"rolling-to-servers" => true,
"max-failure-percentage" => 20
},
"groupB" => undefined
},
"server-group" => {
"groupC" => {
"rolling-to-servers" => false,
"max-failed-servers" => 1
}
}
},
{"server-group" => {"groupC" => undefined}},
{
"concurrent-groups" => {
"groupD" => {
"rolling-to-servers" => true,
"max-failure-percentage" => 20
},
"groupE" => undefined
}
}
]},
"rollback-across-groups" => true
}
}
}
As you can see, the rollout plan is another structure in the operation-headers section. The root node of the structure allows two children:
* in-series -- a list -- A list of steps that are to be performed in series, with each step reaching completion before the next step is executed. Each step involves the application of the operation to the servers in one or more server groups. See below for details on each element in the list.
* rollback-across-groups -- boolean -- indicates whether the need to rollback the operation on all the servers in one server group should trigger a rollback across all the server groups. This is an optional setting, and defaults to false.
Each element in the list under the in-series node must have one or the other of the following structures:
* concurrent-groups -- a map of server group names to policies controlling how the operation should be applied to that server group. For each server group in the map, the operation may be applied concurrently. See below for details on the per-server-group policy configuration.
* server-group -- a single key/value mapping of a server group name to a policy controlling how the operation should be applied to that server group. See below for details on the policy configuration. +(Note: there is no difference in plan execution between this and a "concurrent-groups" map with a single entry.)+
The policy controlling how the operation is applied to the servers within a server group has the following elements, each of which is optional:
* rolling-to-servers -- boolean -- If true, the operation will be applied to each server in the group in series. If false or not specified, the operation will be applied to the servers in the group concurrently.
* max-failed-servers -- int -- Maximum number of servers in the group that can fail to apply the operation before it should be reverted on all servers in the group. The default value if not specified is zero; i.e. failure on any server triggers rollback across the group.
* max-failure-percentage -- int between 0 and 100 -- Maximum percentage of the total number of servers in the group that can fail to apply the operation before it should be reverted on all servers in the group. The default value if not specified is zero; i.e. failure on any server triggers rollback across the group.
If both max-failed-servers and max-failure-percentage are set to non-zero values, max-failure-percentage takes precedence.
Looking at the (contrived) example above, application of the operation to the servers in the domain would be done in 3 phases. If the policy for any server group triggers a rollback of the operation across the server group, all other server groups will be rolled back as well. The 3 phases are:
1. Server groups groupA and groupB will have the operation applied concurrently. The operation will be applied to the servers in groupA in series, while all servers in groupB will handle the operation concurrently. If more than 20% of the servers in groupA fail to apply the operation, it will be rolled back across that group. If any servers in groupB fail to apply the operation it will be rolled back across that group.
2. Once all servers in groupA and groupB are complete, the operation will be applied to the servers in groupC. Those servers will handle the operation concurrently. If more than one server in groupC fails to apply the operation it will be rolled back across that group.
3. Once all servers in groupC are complete, server groups groupD and groupE will have the operation applied concurrently. The operation will be applied to the servers in groupD in series, while all servers in groupE will handle the operation concurrently. If more than 20% of the servers in groupD fail to apply the operation, it will be rolled back across that group. If any servers in groupE fail to apply the operation it will be rolled back across that group.
h3. Default Rollout Plan
All operations that impact multiple servers will be executed with a rollout plan. However, actually specifying the rollout plan in the operation request is not required. If no rollout-plan is specified, a default plan will be generated. The plan will have the following characteristics:
* There will only be a single high level phase. All server groups affected by the operation will have the operation applied concurrently.
* Within each server group, the operation will be applied to all servers concurrently.
* Failure on any server in a server group will cause rollback across the group.
* Failure of any server group will result in rollback of all other server groups.
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