App¶
An application launcher is a resource. As such, it supports the standard start, stop and status actions. Application resources are also involved in the push appinfo action. Application launchers can support the following parameters:
Service action |
Launcher parameter |
|---|---|
start |
start |
stop |
stop |
status print status json status |
status |
push appinfo |
info |
As a resource, an application launcher can be defined with a <svcname>.conf section. This method permits complex application scheduling, mixing chaining and parallel execution, timeouts setting and scoping.
For simple cases, the agent also supports a SysV-style launcher definitions.
Definition¶
Section Syntax¶
Here is a complete application resource section:
[app#1]
script = weblogic
start = true
stop = true
check = true
info = weblogic.info arg1
disable = false
optional = true
tags = group1
subset = web
# rlimits
limit_as = 1g
limit_cpu = 1-4
limit_core = 1-4
limit_data = 1g
limit_fsize = 5t
limit_memlock = 1k
limit_nofile = 10k
limit_nproc = 10k
limit_rss = 100m
limit_stack = 10m
limit_vmem = 100m
All these parameters support scoping, using the @<nodename>, @nodes, @drpnodes and @encapnodes suffixes.
Parameter |
Type |
Role |
|---|---|---|
script |
string |
Full path the the app launcher or basename of a launcher in |
start |
boolean or command |
Flag the app launcher for execution with the start parameter on service startup.
If set to a command, it is executed instead of the default |
stop |
boolean or command |
Flag the app launcher for execution with the stop parameter on service stop.
If set to a command, it is executed instead of the default |
status |
boolean or command |
Flag the app launcher for execution with the status parameter on service status evaluation.
If set to a command, it is executed instead of the default |
info |
boolean or command |
Flag the app launcher for execution with the info parameter on service push appinfo.
If set to a command, it is executed instead of the default |
subset |
string |
Add the resource to the specified app subset. In the given example, the full subset name is subset#app:web |
limit_* |
string |
Refer to the OS |
Subsets¶
Actions on subsets are chained in alphanumeric subset name order on start, status and info.
Actions on subsets are chained in reverse alphanumeric subset name order on stop.
The implicit subset name is
subset#app.Scripts in a subset are executed either in parallel or serially (default).
Here is a subset section:
[subset#app:web]
parallel = true
Application can be started and stopped without touching the other service resources with:
om myservice stop --rid app
om myservice start --rid app
The OPENSVC_SVCNAME variable is set by OpenSVC to the service name, so that integrators can write reusable launcher scripts. Examples of this variable usage below.
Environment variable named OPENSVC_IP<n> are also set to let app launchers bind the appropriate service ips, for services with instances on different subnets. For example, the service might have a different ip address when starting on the disaster recovery site.
Launcher Scripts Development Guidelines¶
A single-launcher script should support the following values for argument 1:
Arg1 |
Description |
|---|---|
start |
Triggers the application startup. The return code must be 0 for a succesful startup, and not 0 otherwise. |
stop |
Triggers the application shutdown. The return code must be 0 for a succesful shutdown, and not 0 otherwise. |
status |
Return 0 if the application is up, or any other value if the application is not up. In this later case, the agent will report a warn status for the resource. |
info |
Emits on stdout |