nbdkit-retry-request-filter - Man Page

 nbdkit --filter=retry-request PLUGIN
                   [retry-request-retries=N] [retry-request-delay=N]
                   [retry-request-open=false]

nbdkit-retry-request-filter is a filter for nbdkit that transparently retries single requests if they fail.  This is useful for plugins that are not completely reliable or have random behaviour. For example nbdkit-curl-plugin(1) might behave this way if pointed at a load balancer which sometimes redirects to a web server that is not responsive.

An alternative filter with different trade-offs is nbdkit-retry-filter(1).  That filter is more heavyweight because it always reopens the whole plugin connection on failure.

retry-request-retries=N

The number of times any single request will be retried before we give up and fail the operation.  The default is 2.

retry-request-delay=DELAY

The time to wait before retrying.  The default is 2 seconds.  Any format supported by nbdkit_parse_delay(3) is allowed here.

retry-request-open=false

If set to false, do not retry opening the plugin.  The default is to treat plugin open in the same way as other requests.

$filterdir/nbdkit-retry-request-filter.so

The filter.

Use nbdkit --dump-config to find the location of $filterdir.

nbdkit-retry-filter first appeared in nbdkit 1.30.

nbdkit(1), nbdkit-filter(3), nbdkit-readahead-filter(1), nbdkit-retry-filter(1), nbdkit_parse_delay(3).

Richard W.M. Jones

Copyright Red Hat

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

nbdkit(1), nbdkit-captive(1), nbdkit-curl-plugin(1), nbdkit-error-filter(1), nbdkit-filter(3), nbdkit-release-notes-1.30(1), nbdkit-release-notes-1.36(1), nbdkit-release-notes-1.40(1), nbdkit-retry-filter(1).