$ kudu-master --help
To configure the behavior of each Kudu process, you can pass command-line flags when
you start it, or read those options from configuration files by passing them using
one or more --flagfile=<file> options. You can even include the
--flagfile option within your configuration file to include other files. Learn more about gflags
by reading its documentation.
You can place options for masters and tablet servers into the same configuration file, and each will ignore options that do not apply.
Flags can be prefixed with either one or two - characters. This
documentation standardizes on two: --example_flag.
Only the most common configuration options are documented here. For a more exhaustive list of configuration options, see the Configuration Reference.
To see all configuration flags for a given executable, run it with the --help option.
Take care when configuring undocumented flags, as not every possible
configuration has been tested, and undocumented options are not guaranteed to be
maintained in future releases.
Every Kudu node requires the specification of directory flags. The
--fs_wal_dir configuration indicates where Kudu will place its write-ahead
logs. The --fs_metadata_dir configuration indicates where Kudu will place
metadata for each tablet. It is recommended, although not necessary, that these
directories be placed on a high-performance drives with high bandwidth and low
latency, e.g. solid-state drives. If --fs_metadata_dir is not specified,
metadata will be placed in the directory specified by --fs_wal_dir. Since
a Kudu node cannot tolerate the loss of its WAL or metadata directories, it
may be wise to mirror the drives containing these directories in order to
make recovering from a drive failure easier; however, mirroring may increase
the latency of Kudu writes.
The --fs_data_dirs configuration indicates where Kudu will write its data
blocks. This is a comma-separated list of directories; if multiple values are
specified, data will be striped across the directories. If not specified, data
blocks will be placed in the directory specified by --fs_wal_dir. Note that
while a single data directory backed by a RAID-0 array will outperform a single
data directory backed by a single storage device, it is better to let Kudu
manage its own striping over multiple devices rather than delegating the
striping to a RAID-0 array.
Additionally, --fs_wal_dir and --fs_metadata_dir may be the same as one
of the directories listed in --fs_data_dirs, but must not be sub-directories
of any of them.
| Each directory specified by a configuration flag on a given machine should be used by at most one Kudu process. If multiple Kudu processes on the same machine are configured to use the same directory, Kudu may refuse to start up. |
Once --fs_data_dirs is set, extra tooling is required to change it.
For more details, see the Kudu
Administration docs.
|
The --fs_wal_dir and --fs_metadata_dir configurations can be changed,
provided the contents of the directories are also moved to match the flags.
|
To see all available configuration options for the kudu-master executable, run it
with the --help option:
$ kudu-master --help
| Flag | Valid Options | Default | Description |
|---|---|---|---|
|
string |
|
Comma-separated list of all the RPC addresses for Master consensus-configuration. If not specified, assumes a standalone Master. |
|
string |
List of directories where the Master will place its data blocks. |
|
|
string |
The directory where the Master will place its tablet metadata. |
|
|
string |
The directory where the Master will place its write-ahead logs. |
|
|
string |
|
The directory to store Master log files. |
For the full list of flags for masters, see the Kudu Master Configuration Reference.
To see all available configuration options for the kudu-tserver executable,
run it with the --help option:
$ kudu-tserver --help
| Flag | Valid Options | Default | Description |
|---|---|---|---|
--fs_data_dirs |
string |
List of directories where the Tablet Server will place its data blocks. |
|
--fs_metadata_dir |
string |
The directory where the Tablet Server will place its tablet metadata. |
|
--fs_wal_dir |
string |
The directory where the Tablet Server will place its write-ahead logs. |
|
--log_dir |
string |
/tmp |
The directory to store Tablet Server log files |
--tserver_master_addrs |
string |
|
Comma separated addresses of the masters which the tablet server should connect to. The masters do not read this flag. |
--block_cache_capacity_mb |
integer |
512 |
Maximum amount of memory allocated to the Kudu Tablet Server’s block cache. |
--memory_limit_hard_bytes |
integer |
4294967296 |
Maximum amount of memory a Tablet Server can consume before it starts rejecting all incoming writes. |
For the full list of flags for tablet servers, see the Kudu Tablet Server Configuration Reference.
Kudu allows certain configurations to be set per table. To configure the behavior of a Kudu table, you can set these configurations at table creation, or alter them via the Kudu API or Kudu command line tool.
| Configuration | Valid Options | Default | Description |
|---|---|---|---|
kudu.table.history_max_age_sec |
integer |
Number of seconds to retain history for tablets in this table. |