MySQL Enterprise Backup User's Guide (Version 8.4.0)
There are two options for controlling the progress reporting
function of mysqlbackup:
--show-progress and
--progress-interval:
--show-progress[={stderr|stdout|file:FILENAME|fifo:FIFONAME|table|variable}]
| Command-Line Format | --show-progress[=destinations] |
|---|---|
| Type | Enumeration |
| Valid Values |
|
The option instructs mysqlbackup to periodically output short progress reports known as progress indicators on its operation.
The argument of the option controls the destination to which the progress indicators are sent:
stderr: Progress indicators are sent
to the standard error stream. The report is embedded in
a time-stamped mysqlbackup INFO
message. For example:
130607 12:22:38 mysqlbackup: INFO: Progress: 191 of 191 MB; state: Completed
stdout: Progress indicators are sent
to the standard output stream. A single newline
character is printed after each progress indicator.
file:FILENAME: Progress indicators
are sent to a file. Each new progress report overwrites
the file, and the file contains the most recent progress
indicator followed by a single newline character.
fifo:FIFONAME: Progress indicators
are sent to a file system FIFO. A single newline
character is printed after each progress indicator.
If there is no process reading the FIFO, the mysqlbackup process hangs at the end of the execution.
table: Progress indicators are sent
to the mysql.backup_progress table.
This requires a connection to the MySQL server, and
therefore, only works when backing up a running MySQL
instance. mysqlbackup first adds one
row of the progress report to the
mysql.backup_progress table, and then
updates the row afterwards with the latest progress
indicator. The progress indicator is stored in the
current_status column of the table.
variable: Progress indicators are
sent to the system variable
backup_progress.
The system variable
backup_progress is not yet
defined for the MySQL Server. Users need to create
their own plugin to define the variable. See
The MySQL Plugin API for more information on
user plugins.
When there is no argument specified for
--show-progress, progress indicators are
sent to stderr.
Progress can be reported to multiple destinations by
specifying the --show-progress option
several times on the command line. For example the following
command line reports progress of the backup command to
stderr and to a file called
meb_output:
mysqlbackup --show-progress --show-progress=file:meb_output --backup-dir=/full-backup
backup
The progress indicators are short strings that indicate how far the execution of a mysqlbackup operation has progressed. A progress indicator consists of one or more meters that measure the progress of the operation. For example:
Progress: 100 of 1450 MB; state: Copying .ibd files
This shows that 100 megabytes of a total of 1450 megabytes
have been copied or processed so far, and
mysqlbackup is currently copying InnoDB
data files (.ibd files).
The progress indicator string begins with
Progress:, followed by one or more meters
measuring the progress. If multiple meters are present, they
are separated by semicolons. The different types of meters
include:
Total data meter: It is always the first meter in the progress indicator. It is in the format of:
DATA of TOTAL UNIT
DATA and TOTAL are unsigned decimal integers, and UNIT is either MB (megabytes), KB (kilobytes), or bytes (1MB=1024KB and 1KB=1024 bytes).
The total data meter has two slightly different meanings depending on the mysqlbackup operation:
The amount of data copied or processed and the total amount of data to be copied or processed by the mysqlbackup operation. For example:
Progress: 200 of 1450 MB
When the operation is for, e.g.,
backup, the indicator
means 200MB is copied of 1450MB. But when the
operation is for, e.g.,
validate or
incremental, it means
200MB is processed out of 1450MB.
Total amount of data copied or processed and an estimate for the total that will be copied by the end of the operation. The estimated total is updated as per the data on the server, as the execution of the command progresses.
For some operations such as
backup, it is not
possible to know exactly at the start of the
execution how much data will be copied or processed.
Therefore, the total data meter shows the estimated
amount of the total data for a backup. The estimate
is updated during the execution of the command. For
example:
Progress: 200 of 1450 MB
is followed by:
Progress: 200 of 1550 MB
when 100MB of data is added on the server.
If the operation is successful, the final progress indicator shows the actual amount of data copied at the end of the operation.
Compression meter: It indicates the sliding average of
the compression ratio, which is defined for each block
of data that is compressed as (orig_size -
compressed_size) / orig_size. For example:
compression: 40%
This means that after compression, the data takes 40% less space (calculated as an average over the last 10 data blocks).
The compression meter is included in the progress
indicator if the --compress
option is enabled for the mysqlbackup
operation. The value of the compression meter is
undefined until at least 10 data blocks have been
compressed. The undefined meter value is denoted by the
'-' in the meter:
compression: -
State meter: It is a short description of the major step the command is currently executing. For example:
state: Copying InnoDB data
state: Waiting for locks
state: Copying system tablespace
state: Copying .ibd files
state: Copying non-InnoDB data
state: Completed
Here are some examples of progress indicators with different meters:
Progress: 300 of 1540 MB; state: Waiting for locks
Progress: 400 of 1450 MB; state: Copying InnoDB data: compression: 30%
The exact set of meters included in the progress indicator depends on the command and the options used for it.
| Command-Line Format | --progress-interval=SECONDS |
|---|---|
| Type | Numeric |
| Default Value | 2 |
| Minimum Value | 1 |
| Maximum Value | 100000 |
| Unit | second |
Interval between progress reports in seconds. Default value is two seconds. The shortest interval is 1 second and the longest allowed interval is 100000 seconds.