Trace Event Script Processing on Devices Running Junos OS
Event script tracing operations track event script operations and record them in a log file. The logged error descriptions provide detailed information to help you solve problems faster.
On Junos OS, the default operation of event script tracing is to log important events, which include errors, warnings, progress messages, and script processing events, in the /var/log/escript.log file on the device. When the file escript.log reaches 128 kilobytes (KB), it is renamed with a number 0 through 9 (in ascending order) appended to the end of the file and then compressed. The resulting files are escript.log.0.gz, then escript.log.1.gz, until there are 10 trace files. Then the oldest trace file (escript.log.9.gz) is overwritten.
Junos OS Evolved captures trace data for all
applications by default and collects the data for all script types in trace files that
correspond to the cscript
application. To view the trace data, issue
the show trace application cscript
command. For more information, see
Trace Script Processing on Devices Running Junos OS Evolved.
Minimum Configuration for Enabling Traceoptions for Event Scripts
If no event script trace options are configured, the simplest way to view the trace
output of an event script is to configure the output
trace flag and
issue the show log escript.log | last
command. To do this, perform
the following steps:
If you have not done so already, enable an event script by including the
file
statement at the[edit event-options event-script]
hierarchy level:[edit event-options event-script] user@host# set file filename
Enable trace options by including the
traceoptions flag output
statement at the[edit event-options event-script]
hierarchy level:[edit event-options event-script] user@host# set traceoptions flag output
Commit the configuration.
[edit] user@host# commit and-quit
Display the resulting trace messages recorded in the /var/log/escript.log file. At the end of the log is the output generated by the event script you enabled in Step 1 after a configured event policy is triggered and invokes the script. To display the end of the log, issue the
show log escript.log | last
operational mode command:user@host> show log escript.log | last
Table 1 summarizes useful filtering commands that display selected portions of the escript.log file.
Task |
Command |
---|---|
Display logging data associated with all event script processing. |
|
Display processing for only the most recent operation. |
|
Display processing for script errors. |
|
Display processing for a particular script. |
|
Example: Minimum Configuration for Enabling Traceoptions for Event Scripts
Display the trace output of the event script file source-route.xsl:
[edit] event-options { event-script { file source-route.xsl; traceoptions { flag output; } } }
[edit] user@host# commit and-quit
user@host> show log escript.log | last
Configure Tracing of Event Scripts
You cannot change the directory (/var/log) to which trace files
are written. However, you can customize other trace file settings by including the
following statements at the [edit event-options event-script
traceoptions]
hierarchy level:
[edit event-options event-script traceoptions] file <filename> <files number> <size size> <world-readable | no-world-readable>; flag all; flag events; flag input; flag offline; flag output; flag rpc; flag xslt; no-remote-trace;
These statements are described in the following sections:
- Configure the Event Script Log Filename
- Configure the Number and Size of Event Script Log Files
- Configure Access to Event Script Log Files
- Configure the Event Script Trace Operations
Configure the Event Script Log Filename
By default, the name of the file that records trace output for event scripts is
escript.log. You can specify a different name by
including the file
statement at the [edit event-options
event-script traceoptions]
hierarchy level:
[edit event-options event-script traceoptions] file filename;
Configure the Number and Size of Event Script Log Files
By default, when the trace file reaches 128 KB in size, it is renamed and compressed to filename.0.gz, then filename.1.gz, and so on, until there are 10 trace files. Then the oldest trace file (filename.9.gz) is overwritten.
You can configure the limits on the number and size of trace files by including
the following statements at the [edit event-options event-script
traceoptions file filename]
hierarchy level:
[edit event-options event-script traceoptions file filename] files number size size;
For example, set the maximum file size to 640 KB and the maximum number of files to 20. When the file that receives the output of the tracing operation (filename) reaches 640 KB, it is renamed and compressed to filename.0.gz, and a new file called filename is created. When filename reaches 640 KB, filename.0.gz is renamed filename.1.gz and filename is renamed and compressed to filename.0.gz. This process repeats until there are 20 trace files. Then the oldest file (filename.19.gz) is overwritten.
The number of files can range from 2 through 1000 files. The file size can range from 10 KB through 1 gigabyte (GB).
If you set either a maximum file size or a maximum number of trace files, you also must specify the other parameter and a filename.
Configure Access to Event Script Log Files
By default, access to the event script log file is restricted to the owner. You
can manually configure access by including the world-readable
or no-world-readable
statement at the [edit
event-options event-script traceoptions
file filename]
hierarchy level.
[edit event-options event-script traceoptions file filename] (world-readable | no-world-readable);
The no-world-readable
statement restricts event script log
access to the owner. The world-readable
statement enables
unrestricted access to the event script log file.
Configure the Event Script Trace Operations
By default, the traceoptions events
flag is turned on,
regardless of the configuration settings, and only important events are logged.
This includes errors, warnings, progress messages, and script processing events.
You can configure the trace operations to be logged by including the following
statements at the [edit event-options event-script
traceoptions]
hierarchy level:
[edit event-options event-script traceoptions] flag all; flag events; flag input; flag offline; flag output; flag rpc; flag xslt;
Table 2 describes the meaning of the event script tracing flags.
Flag |
Description |
Default Setting |
---|---|---|
|
Trace all operations. |
Off |
|
Trace important events, including errors, warnings, progress messages, and script processing events. |
On |
|
Trace event script input data. |
Off |
|
Generate data for offline development. |
Off |
|
Trace event script output data. |
Off |
|
Trace event script RPCs. |
Off |
|
Trace the Extensible Stylesheet Language Transformations (XSLT) library. |
Off |