Grid Storage Probe

The check_gridstorage probe can check file operations against grid storage protocols, including SRM, GridFTP, LFC, and other protocols supported by arccp and arcls.

The main configuration section of this probe is gridstorage, see Configuration Files. This probe requires an X509 proxy, see Proxy Certificate.

Basic Invocation

To perform read-only checks against a URL pointing to an existing file, use:

check_gridstorage --url <url>

To perform read-write checks against an URL, use either:

check_gridstorage --url <url> --enable-write
check_gridstorage -H <hostname> --dir-url <url> --enable-write

In the latter case, the probe will add a file name based on the host name and a time stamp. The --dir-url=<url> option will not work correctly with the LFC protocol, since the file name needs to be encoded inside the URL.

Performed Checks

The probe will do the following checks:

  • If writing is enabled, a small is generated at copied to the provided URL. The contents of the file includes the time and host name passed to -H or “localhost”.
  • The URL is listed and it’s checked that the listing contains the name of the uploaded file.
  • The file is read back.
  • If writing is enabled, the content is compared to what was written. Since the content contains as host name and a time stamp, it’s unlikely that an old file is accidentally matched.
  • If writing is enabled, the file is deleted.

Any failure in the above checks will return CRITICAL to Nagios.

Additional Options

If you wish to do a more thorough list-test, you can ask the probe to list the whole directory containing the test file. This is done by passing --list-dir. This will use --dir-url=<url> if specified, otherwise it will guess the URL of the containing directory by stripping off the last component of --url=<url>. In any case, the listed URL must contain the test-file. Be aware that if the directory contains many entries, the probe may time out.

You can disable the read or list tests with --disable-read and --disable-list.

LFC Invocation

LFC tests are special in that write operations associate a logical path with a physical storage. The probe therefore allows passing an URL to be used only for the write operation, so the write-enabled test should look something like

check_gridstorage \
    --enable-write \
    --write-url=lfc://<physical-url>@<lfc-host>/<logical-path> \
    --url=lfc://<lfc-host>/<logical-path> \