[[Canceling_Management_Operations]]
= Canceling Management Operations

WildFly includes the ability to use the CLI to cancel management
requests that are not proceeding normally.

[[the-cancel-non-progressing-operation-operation]]
== The cancel-non-progressing-operation operation

The `cancel-non-progressing-operation` operation instructs the target
process to find any operation that isn't proceeding normally and cancel
it.

On a standalone server:

[source,options="nowrap"]
----
[standalone@localhost:9990 /] /core-service=management/service=management-operations:cancel-non-progressing-operation
{
    "outcome" => "success",
    "result" => "-1155777943"
}
----

The result value is an internal identification number for the operation
that was cancelled.

On a managed domain host controller, the equivalent resource is in the
host=<hostname> portion of the management resource tree:

[source,options="nowrap"]
----
[domain@localhost:9990 /] /host=host-a/core-service=management/service=management-operations:cancel-non-progressing-operation
{
    "outcome" => "success",
    "result" => "2156877946"
}
----

An operation can be cancelled on an individual managed domain server as
well:

[source,options="nowrap"]
----
[domain@localhost:9990 /] /host=host-a/server=server-one/core-service=management/service=management-operations:cancel-non-progressing-operation
{
    "outcome" => "success",
    "result" => "6497786512"
}
----

An operation is considered to be not proceeding normally if it has been
executing with the exclusive operation lock held for longer than 15
seconds. Read-only operations do not acquire the exclusive operation
lock, so this operation will not cancel read-only operations. Operations
blocking waiting for another operation to release the exclusive lock
will also not be cancelled.

If there isn't any operation that is failing to proceed normally, there
will be a failure response:

[source,options="nowrap"]
----
[standalone@localhost:9990 /] /core-service=management/service=management-operations:cancel-non-progressing-operation
{
    "outcome" => "failed",
    "failure-description" => "WFLYDM0089: No operation was found that has been holding the operation execution write lock for long than [15] seconds",
    "rolled-back" => true
}
----

[[the-find-non-progressing-operation-operation]]
== The find-non-progressing-operation operation

To simply learn the id of an operation that isn't proceeding normally,
but not cancel it, use the `find-non-progressing-operation` operation:

[source,options="nowrap"]
----
[standalone@localhost:9990 /] /core-service=management/service=management-operations:find-non-progressing-operation
{
    "outcome" => "success",
    "result" => "-1155777943"
}
----

If there is no non-progressing operation, the outcome will still be
`success` but the result will be `undefined`.

Once the id of the operation is known, the management resource for the
operation can be examined to learn more about its status.

[[examining-the-status-of-an-active-operation]]
== Examining the status of an active operation

There is a management resource for any currently executing operation
that can be queried:

[source,options="nowrap"]
----
[standalone@localhost:9990 /] /core-service=management/service=management-operations/active-operation=-1155777943:read-resource(include-runtime=true)
{
    "outcome" => "success",
    "result" => {
        "access-mechanism" => "undefined",
        "address" => [
            ("deployment" => "example")
        ],
        "caller-thread" => "management-handler-thread - 24",
        "cancelled" => false,
        "exclusive-running-time" => 101918273645L,
        "execution-status" => "awaiting-stability",
        "operation" => "deploy",
        "running-time" => 101918279999L
    }
}
----

The response includes the following attributes:

[cols=",",options="header"]
|=======================================================================
|Field |Meaning

|access-mechanism |The mechanism used to submit a request to the server.
NATIVE, JMX, HTTP

|address |The address of the resource targeted by the operation. The
value in the final element of the address will be '<hidden>' if the
caller is not authorized to address the operation's target resource.

|caller-thread |The name of the thread that is executing the operation.

|cancelled |Whether the operation has been cancelled.

|`exclusive-status` |Amount of time in nanoseconds the operation has
been executing with the exclusive operation execution lock held, or -1
if the operation does not hold the exclusive execution lock.

|execution-status |The current activity of the operation. See below for
details.

|operation |The name of the operation, or '<hidden>' if the caller is
not authorized to address the operation's target resource.

|running-time |Amount of time the operation has been executing, in
nanoseconds.
|=======================================================================

The following are the values for the `exclusive-running-time` attribute:

[cols=",",options="header"]
|=======================================================================
|Value |Meaning

|executing |The caller thread is actively executing

|awaiting-other-operation |The caller thread is blocking waiting for
another operation to release the exclusive execution lock

|awaiting-stability |The caller thread has made changes to the service
container and is waiting for the service container to stabilize

|completing |The operation is committed and is completing execution

|rolling-back |The operation is rolling back
|=======================================================================

All currently executing operations can be viewed in one request using
the `read-children-resources` operation:

[source,options="nowrap"]
----
[standalone@localhost:9990 /] /core-service=management/service=management-operations:read-children-resources(child-type=active-operation)
{
    "outcome" => "success",
    "result" => {"-1155777943" => {
        "access-mechanism" => "undefined",
        "address" => [
            ("deployment" => "example")
        ],
        "caller-thread" => "management-handler-thread - 24",
        "cancelled" => false,
        "exclusive-running-time" => 101918273645L,
        "execution-status" => "awaiting-stability",
        "operation" => "deploy",
        "running-time" => 101918279999L
    },
    {"-1246693202" => {
        "access-mechanism" => "undefined",
        "address" => [
            ("core-service" => "management"),
            ("service" => "management-operations")
        ],
        "caller-thread" => "management-handler-thread - 30",
        "cancelled" => false,
        "exclusive-running-time" => -1L,
        "execution-status" => "executing",
        "operation" => "read-children-resources",
        "running-time" => 3356000L
    }}
}
----

[[canceling-a-specific-operation]]
== Canceling a specific operation

The `cancel-non-progressing-operation` operation is a convenience
operation for identifying and canceling an operation. However, an
administrator can examine the active-operation resources to identify any
operation, and then directly cancel it by invoking the `cancel`
operation on the resource for the desired operation.

[source,options="nowrap"]
----
[standalone@localhost:9990 /] /core-service=management/service=management-operations/active-operation=-1155777943:cancel
{
    "outcome" => "success",
    "result" => undefined
}
----

[[controlling-operation-blocking-time]]
== Controlling operation blocking time

As an operation executes, the execution thread may block at various
points, particularly while waiting for the service container to
stabilize following any changes. Since an operation may be holding the
exclusive execution lock while blocking, in WildFly execution behavior
was changed to ensure that blocking will eventually time out, resulting
in roll back of the operation.

The default blocking timeout is 300 seconds. This is intentionally long,
as the idea is to only trigger a timeout when something has definitely
gone wrong with the operation, without any false positives.

An administrator can control the blocking timeout for an individual
operation by using the `blocking-timeout` operation header. For example,
if a particular deployment is known to take an extremely long time to
deploy, the default 300 second timeout could be increased:

[source,options="nowrap"]
----
[standalone@localhost:9990 /] deploy /tmp/mega.war --headers={blocking-timeout=450}
----

Note the blocking timeout is *not* a guaranteed maximum execution time
for an operation. If it only a timeout that will be enforced at various
points during operation execution.
