docs/en/14-reference/02-tools/09-taosdump.md
taosdump is a TDengine data backup/recovery tool provided for open source users, and the backed up data files adopt the standard Apache AVRO
Format, convenient for exchanging data with the external ecosystem.
taosdump provides multiple data backup and recovery options to meet different data needs, and all supported options can be viewed through --help.
taosdump is the default installation component in the TDengine server and client installation package. It can be used after installation, refer to TDengine Installation
taosdump needs to be run in the command line terminal. It must be run with parameters to indicate backup or restore operations, such as:
taosdump -h my-server -D test -o /root/test/
The above command means to backup the test database on the my server machine to the /root/test/ directory.
taosdump -h my-server -i /root/test/
The above command means to restore the previously backed up data files in the /root/test/ directory to the host named my server.
Below is the detailed command line parameters list for taosdump:
Usage: taosdump [OPTION...] dbname [tbname ...]
or: taosdump [OPTION...] --databases db1,db2,...
or: taosdump [OPTION...] --all-databases
or: taosdump [OPTION...] -i inpath
or: taosdump [OPTION...] -o outpath
-h, --host=HOST Server host from which to dump data. Default is
localhost.
-p, --password User password to connect to server. Default is
taosdata.
-P, --port=PORT Port to connect.
-u, --user=USER User name used to connect to server. Default is
root.
-c, --config-dir=CONFIG_DIR Configure directory. Default is /etc/taos.
-i, --inpath=INPATH Input file path.
-o, --outpath=OUTPATH Output file path.
-r, --resultFile=RESULTFILE DumpOut/In Result file path and name.
-a, --allow-sys Allow to dump system database (2.0 only).
-A, --all-databases Dump all databases.
-D, --databases=DATABASES Dump listed databases. Use comma to separate
databases names.
-e, --escape-character Use escaped character for database name.
-N, --without-property Dump database without its properties.
-s, --schemaonly Only dump table schemas.
-d, --avro-codec=snappy Choose an avro codec among null, deflate, snappy,
and lzma(Windows is not currently supported).
-S, --start-time=START_TIME Start time to dump. Either epoch or
ISO8601/RFC3339 format is acceptable. ISO8601
format example: 2017-10-01T00:00:00.000+0800 or
2017-10-0100:00:00:000+0800 or '2017-10-01
00:00:00.000+0800'.
-E, --end-time=END_TIME End time to dump. Either epoch or ISO8601/RFC3339
format is acceptable. ISO8601 format example:
2017-10-01T00:00:00.000+0800 or
2017-10-0100:00:00.000+0800 or '2017-10-01
00:00:00.000+0800'.
-B, --data-batch=DATA_BATCH Number of data per query/insert statement when
backup/restore. Default value is 16384. If you see
'error actual dump .. batch ..' when backup or if
you see 'WAL size exceeds limit' error when
restore, please adjust the value to a smaller one
and try. The workable value is related to the
length of the row and type of table schema.
-I, --inspect inspect avro file content and print on screen.
-L, --loose-mode Use loose mode if the table name and column name
use letter and number only. Default is NOT.
-n, --no-escape No escape char '`'. Default is using it.
-Q, --dot-replace Replace dot character with underline character in
the table name.
-T, --thread-num=THREAD_NUM Number of threads for dump in/out data. Default
is 8.
-W, --rename=RENAME-LIST Rename database name with new name during
importing data. RENAME-LIST:
"db1=newDB1|db2=newDB2" means rename db1 to newDB1
and rename db2 to newDB2.
-C, --cloud=CLOUD_DSN Alias for the -X/--dsn option.
-k, --retry-count=VALUE Set the number of retry attempts for connection or
query failures.
-t, --timeout=SECONDS The timeout seconds for websocket to interact.
-X, --dsn=DSN The dsn to connect the cloud service.
-z, --retry-sleep-ms=VALUE Sleep interval between retries, in milliseconds.
-Z, --driver=DRIVER Connect driver , value can be "Native" or
"WebSocket", default is Native.
-g, --debug Print debug info.
-?, --help Give this help list
--usage Give a short usage message
-V, --version Print program version.
Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.
Report bugs to <[email protected]>.
-A or --all-databases parameter.-D db1,db2,... parameter.dbname stbname1 stbname2 tbname1 tbname2 ... parameter, note that this input sequence starts with the database name, supports only one database, and the second and subsequent parameters are the names of the supertables or basic tables in that database, separated by spaces.log, which contains data for TDengine's own operation, taosdump does not back up the log database by default. If there is a specific need to back up the log database, you can use the -a or --allow-sys command line parameter.-n and -L parameters, used for backing up data without using escape characters and in "tolerant" mode, which can reduce backup data time and space occupied when table names, column names, and label names do not use escape characters. If unsure whether to use -n and -L, use the default parameters for "strict" mode backup. For an explanation of escape characters, please refer to the official documentation-o parameter, to prevent data from being overwritten, taosdump will report an error and exit. Please replace it with another empty directory or clear the original data before backing up.:::tip
-I parameter, used for parsing avro file schema and data, specifying the -s parameter will only parse the schema.-B parameter to specify the number of batches, the default value is 16384. If "Error actual dump .. batch .." occurs due to insufficient network speed or disk performance in some environments, you can try adjusting the -B parameter to a smaller value.:::
-i parameter along with the data file path. As mentioned earlier, the same directory should not be used to back up different data sets, nor should the same path be used to back up the same data set multiple times, otherwise, the backup data will cause overwriting or multiple backups.-W, please refer to the command line parameter description for details.:::tip
taosdump internally uses the TDengine stmt binding API to write restored data, currently using 16384 as a batch for writing. If there are many columns in the backup data, it may cause a "WAL size exceeds limit" error, in which case you can try adjusting the -B parameter to a smaller value.
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