Ubuntu Manpage: glance-scrubber - Glance Scrubber Service

name
glance scrub service
author
copyright

Provided by: glance-api_16.0.1-0ubuntu1.1_all

NAME

       glance-scrubber - Glance Scrubber Service

GLANCE SCRUB SERVICE

Author OpenStack Glance Project Team

Contact
glance@lists.launchpad.net

Date 2018-02-28

Version
16.0.0

Manual section
1

Manual group
cloud computing

SYNOPSIS
glance-scrubber [options]

DESCRIPTION
glance-scrubber is a utility that allows an operator to configure Glance for the asynchronous deletion of
images. Whether this makes sense for your deployment depends upon the storage backend you are using and
the size of typical images handled by your Glance installation.

An image in glance is really a combination of an image record (stored in the database) and a file of
image data (stored in a storage backend). Under normal operation, the image-delete call is synchronous,
that is, Glance receives the DELETE request, deletes the image data from the storage backend, then
deletes the image record from the database, and finally returns a 204 as the result of the call. If the
backend is fast and deletion time is not a function of data size, these operations occur very quickly.
For backends where deletion time is a function of data size, however, the image-delete operation can take
a significant amount of time to complete, to the point where a client may timeout waiting for the
response. This in turn leads to user dissatisfaction.

To avoid this problem, Glance has a delayed_delete configuration option (False by default) that may be
set in the glance-api.conf file. With this option enabled, when Glance receives a DELETE request, it
does only the database part of the request, marking the image's status as pending_delete, and returns
immediately. (The pending_delete status is not visible to users; an image-show request for such an image
will return 404.) However, it is important to note that when delayed_delete is enabled, Glance does not
delete image data from the storage backend. That's where the glance-scrubber comes in.

The glance-scrubber cleans up images that have been deleted. If you run Glance with delayed_delete
enabled, you must run the glance-scrubber occasionally or your storage backend will eventually fill up
with "deleted" image data.

Configuration of glance-scrubber is done in the glance-scrubber.conf file. Options are explained in
detail in comments in the sample configuration file, so we only point out a few of them here.

scrub_time
minimum time in seconds that an image will stay in pending_delete status (default is 0)

scrub_pool_size
configures a thread pool so that scrubbing can be performed in parallel (default is 1, that is,
serial scrubbing)

daemon a boolean indicating whether the scrubber should run as a daemon (default is False)

wakeup_time
time in seconds between runs when the scrubber is run in daemon mode (ignored if the scrubber is
not being run in daemon mode)

metadata_encryption_key
If your glance-api.conf sets a value for this option (the default is to leave it unset), you must
include the same setting in your glance-scrubber.conf or the scrubber won't be able to determine
the locations of your image data.

[database]
As of the Queens release of Glance (16.0.0), the glance-scrubber does not use the deprecated
Glance registry, but instead contacts the Glance database directly. Thus your
glance-scrubber.conf file must contain a [database] section specifying the relevant information.

[glance_store]
This section of the file contains the configuration information for the storage backends used by
your Glance installation.

The usual situation is that whatever your glance-api.conf has for the [database] and [glance_store]
configuration groups should go into your glance-scrubber.conf, too. Of course, if you have heavily
customized your setup, you know better than we do what you are doing. The key thing is that the scrubber
needs to be able to access the Glance database to determine what images need to be scrubbed (and to mark
them as deleted once their associated data has been removed from the storage backend), and it needs the
glance_store information so it can delete the image data.

OPTIONS
General options

-h, --help
Show the help message and exit

--version
Print the version number and exit

-v, --verbose
Print more verbose output

--noverbose
Disable verbose output

-d, --debug
Print debugging output (set logging level to DEBUG instead of default WARNING level)

--nodebug
Disable debugging output

--use-syslog
Use syslog for logging

--nouse-syslog
Disable the use of syslog for logging

--syslog-log-facility SYSLOG_LOG_FACILITY
syslog facility to receive log lines

--config-dir DIR
Path to a config directory to pull *.conf files from. This file set is sorted, to provide a
predictable parse order if individual options are over-ridden. The set is parsed after the
file(s) specified via previous --config-file, arguments hence over-ridden options in the
directory take precedence. This means that configuration from files in a specified
config-dir will always take precedence over configuration from files specified by
--config-file, regardless to argument order.

--config-file PATH
Path to a config file to use. Multiple config files can be specified by using this flag
multiple times, for example, --config-file <file1> --config-file <file2>. Values in latter
files take precedence.

--log-config-append PATH --log-config PATH
The name of logging configuration file. It does not disable existing loggers, but just
appends specified logging configuration to any other existing logging options. Please see
the Python logging module documentation for details on logging configuration files. The
log-config name for this option is deprecated.

--log-format FORMAT
A logging.Formatter log message format string which may use any of the available
logging.LogRecord attributes. Default: None

--log-date-format DATE_FORMAT
Format string for %(asctime)s in log records. Default: None

--log-file PATH, --logfile PATH
(Optional) Name of log file to output to. If not set, logging will go to stdout.

--log-dir LOG_DIR, --logdir LOG_DIR
(Optional) The directory to keep log files in (will be prepended to --log-file)

-D, --daemon
Run as a long-running process. When not specified (the default) run the scrub operation once
and then exits. When specified do not exit and run scrub on wakeup_time interval as specified
in the config.

--nodaemon
The inverse of --daemon. Runs the scrub operation once and then exits. This is the default.

FILES
/etc/glance/glance-scrubber.conf
Default configuration file for the Glance Scrubber

AUTHOR

       OpenStack

COPYRIGHT

       2010-present, OpenStack Foundation.