Tutorial
This page is a tutorial on NLDS covering:
Introduction to the NLDS
The Near-Line Data Store (NLDS) is a multi-tiered storage solution that uses Object Storage as a front end cache to a tape library. Interaction with NLDS is via a HTTP API, with a Python library and command-line client provided to users for programmatic or interactive use.
When a user ingests files to the NLDS, the files are first written to the cache, and a backup is made to tape. When the cache is approaching capacity, a set of policies is interrogated to determine which files will be removed from the cache. When a user GETs a file, the NLDS may have to first transfer the file from tape to the cache, if it has been deleted by the policies. This, in effect, creates a multi-tiered system of hot (disk), warm (cache) and cold (Tape) storage, with a common interface to all. Additionally, and more importantly, it takes the decision of storage location out of the user’s hands; the user only needs to interact with the service itself rather than manually specifying the movement of data between disk, cache, and tape.
The NLDS also provides a searchable catalog of files, with the user able to assign a label and tags to a collection of files.
Figure 1: User view of the Near-Line Data Store
Setting up the NLDS client
Before using the NLDS, a user must install and set-up the NLDS client. For the NLDS installation on JASMIN, the user must also:
Have access to the Object Storage tenancy (cache) they wish to write files to
Be a member of, and have read/write access to, the GroupWorkspace they wish to use for writing to tape
The NLDS client is a command-line program with the name
nlds, which requires installation into the users homespace, preferably into a Python virtual-environment. To installnlds, refer to the page installation.
The nlds client program relies on a configuration file stored in the user’s
home directory with the path ~/.nlds-config. This contains information
needed to connect the client to the NLDS server. For more in-depth information, refer
to the page configuration.
The configuration file has the contents:
{
"user" : {
"default_user" : "{{ user_name }}",
"default_group" : "{{ user_gws }}"
},
"server" : {
"url" : "{{ nlds_api_url }}",
"api" : "{{ nlds_api_version }}"
},
"authentication" : {
"oauth_client_id" : "{{ oauth_client_id }}",
"oauth_client_secret" : "{{ oauth_client_secret }}",
"oauth_token_url" : "{{ oauth_token_url }}",
"oauth_scopes" : "{{ oauth_scopes }}"",
"oauth_token_file_location" : "~/.nlds-token"
},
"object_storage" : {
"tenancy" : "{{ object_store_tenancy }}",
"access_key" : "{{ object_store_access_key }}",
"secret_key" : "{{ object_store_secret_key }}"
}
}
After installing the client, the nlds init command can be used to fill in the
majority of this file. The init command will fill in:
The
serversection.The
authenticationsection.
The user will have to fill in the following sections:
The
user_name.The
user_gws.The value of the
oauth_token_file_locationfield in theauthenticationsection can be changed to a location of the user’s choosing.Fields in the
object_storagesection are generated by the user interacting with the object storage portal to generate theaccess_keyandsecret_keyvalues.
Running the NLDS client for the first time
Once the NLDS client is successfully installed, the user can run it. It is
recommended that you run the init command first, which will fill in the url
and authentication sections of the .nlds-config file for you - see the
relevant seciton for details.
Once initialised, the first time nlds is run on JASMIN the user will be
asked for their username and password. These are the JASMIN username and
password, which the user usually uses to login into JASMIN via
one of the login servers.
The following message will be displayed:
This application uses OAuth2 to authenticate with the server on your behalf.
To do this it needs your username and password.
Your password is not stored. It is used to obtain an access token, which is stored in the file: ~/.nlds-token
Username:
Password:
After entering your JASMIN username and password, the OAuth2 token is created
at the path pointed to by oauth_token_file_location in the ~/.nlds-config
file. The NLDS authorisation system uses refresh tokens to fetch a new token
when the current one has expired
How the NLDS data catalog is organised
When a user PUTs files into the NLDS, a record of those files is kept in a data catalog. This organises the files into Holdings, Transactions and Files, with the ability to add metadata to the Holdings in the form of Tags and Labels.
Figure 2 shows a simplified view of the NLDS data-catalog. This is covered in much more depth in the Catalog Organisation section.
Figure 2: Simplified view of the NLDS data-catalog
Getting help on the NLDS commands
The --help option can be used in conjunction with any command to get help
on that specific command. To get a list of commands, just use the --help
option.
> nlds --help
Usage: nlds [OPTIONS] COMMAND [ARGS]...
Options:
--help Show this message and exit.
Commands:
find Find and list files.
get Get a single file.
getlist Get a number of files specified in a list.
list List holdings.
meta Alter metadata for a holding.
put Put a single file.
putlist Put a number of files specified in a list.
stat List transactions.
> nlds find --help
Usage: nlds find [OPTIONS]
Find and list files. If no user or group is given then these values will
default to the ``user:default_user`` and ``user:default values`` in the
``~/.nlds-config file``.
Options:
-u, --user TEXT The username to find files for.
-g, --group TEXT The group to find files for.
-l, --label TEXT The label of the holding which the files belong
to. This can be a regular expression (regex).
-i, --holding_id INTEGER The numeric id of the holding which the files
belong to.
-n, --transaction_id TEXT The UUID transaction id of the transaction to
list.
-p, --path TEXT The path of the files to find. This can be a
regular expression (regex)
-t, --tag TAG The tag(s) of the holding(s) to find files
within.
-j, --json Output the result as JSON.
--help Show this message and exit.
Copying a single file (PUT) to the NLDS
To put a single file into the NLDS use the command:
> nlds put <filepath>
This is the simplest form of the command and will PUT the file into a holding
with a seemingly random label. It will also use the values of user and
group from the Configuration File.
To specify the user and group:
> nlds put -u <name> -g <group> <filepath>
To give the newly created holding a sensible label:
> nlds put -l <label> <filepath>
(-u and -g can also be used at the same time as -l).
To add tags to the holding while PUTting a file to the NLDS:
> nlds put -l <label> -t <key:value> <filepath>
(-l is optional here).
To specify a job label use -b <job_label>. This is a convenience function
for the user to allow them to group multiple transactions under a single
job_label.
To get the return output from the put command in JSON format, specify the
-j option.
When a command is invoked, NLDS will return a summary of the command, including
the transaction_id.
> nlds put -l SheepPen /Users/frjohn/sheep.txt -u frjohn -g farmers -b SheepHerding -t sheepdog:skye
PUT transaction accepted for processing.
user : frjohn
group : farmers
action : put
job label : SheepHerding
transaction id : c31abca8-2bc4-43dc-ac64-7d28359d6828
label : SheepPen
tags : sheepdog : skye
Copying a list of files (PUTLIST) to the NLDS
To PUT more than one file into the NLDS, use the putlist command. This
takes the same options as the put command but, rather than taking the path
of a single file as an argument, it takes the name of a plain text file which
contains the paths of the files to PUT into the NLDS. This filelist file must
be in plain text format, with the path of a single file per line, for example:
/Users/frjohn/albatross.txt
/Users/frjohn/rabbit.txt
The command and response then becomes (where test_putlist is the name of the
above file):
> nlds putlist -l Zoo test_list -u frjohn -g farmers -b test_putlist -t zoo:Bristol
PUT transaction accepted for processing.
user : frjohn
group : farmers
action : put
job label : test_putlist
transaction id : 41d412e2-1c1b-4d59-943a-40d9e717a0a1
label : Zoo
tags : zoo : Bristol
Querying the status of a transaction (STAT)
The put and putlist commands above create transactions. These are
actions in the NLDS that carry out a specific task, usually either a put,
putlist, get or getlist command. To view the status of a
transaction, use the stat command. Invoke the stat command on its
own to view the state of all the transactions for a user:
> nlds stat
State of transactions for user:frjohn, group:farmers
id action job label label state last update
1 put SheepHerding SheepPen COMPLETE 2023-04-18 15:21:41
2 put test_putlist Zoo COMPLETE 2023-04-18 15:28:53
(the user_name and group have not been specified with the -u and
-g arguments here, and so the defaults are read from the
Configuration File.)
This table shows the numeric id, the action which created the
transaction, the user-specified job label, the holding label, the last
time the state was updated and the state of the transaction.
As the transaction is processed by the NLDS, it goes through a number of states and will end with a terminating state. All possible states are listed on the Status Codes page. The terminating states are:
COMPLETEFAILEDCOMPLETE_WITH_ERRORSCOMPLETE_WITH_WARNINGS
Results for the stat command can be filtered using the following options:
-b: filter on the user-specifiedjob label.-s: filter on thestate. See Status Codes for a list of possible values.-a: filter on the api action. Options areget,putgetlistandputlist.
> nlds stat -s COMPLETE
State of transactions for user:frjohn, group:farmers, state:COMPLETE
id action job label label state last update
1 put SheepHerding SheepPen COMPLETE 2023-04-18 15:21:41
2 put test_putlist Zoo COMPLETE 2023-04-18 15:28:53
> nlds stat -a put
State of transactions for user:frjohn, group:farmers, api-action:put
id action job label label state last update
1 put SheepHerding SheepPen COMPLETE 2023-04-18 15:21:41
2 put test_putlist Zoo COMPLETE 2023-04-18 15:28:53
> nlds stat -b SheepHerding
State of transaction for user:frjohn, group:farmers
id : 1
user : frjohn
group : farmers
action : put
transaction id : ebb89e7d-5671-41f9-9f42-968fa69b0c87
label : SheepPen
creation time : 2023-04-18 15:21:36
state : COMPLETE
warnings :
sub records ->
+ id : 1
sub_id : 19ccd443-e269-465d-b0ed-51c5e98b8fad
state : COMPLETE
retries : 0
last update : 2023-04-18 15:21:41
In the last example, only one transaction was found, and so the entire details
for a single transaction was returned. If more than one transaction had the
same job_label, then the list format would be returned.
To guarantee to get the full information for a single transaction, the -i
option can be used with the numeric id of the transaction. The -n option
can also be used with the transaction id, if you know it.
> nlds stat -i 2
State of transaction for user:frjohn, group:farmers, id:2
id : 2
user : frjohn
group : farmers
action : put
transaction id : 41d412e2-1c1b-4d59-943a-40d9e717a0a1
label : Zoo
creation time : 2023-04-18 15:28:48
state : COMPLETE
warnings :
sub records ->
+ id : 2
sub_id : 8d457f6c-f26c-43db-98ff-7c2efe7ff695
state : COMPLETE
retries : 0
last update : 2023-04-18 15:28:53
> nlds stat -n 41d412e2-1c1b-4d59-943a-40d9e717a0a1
State of transaction for user:frjohn, group:farmers, transaction_id:41d412e2-1c1b-4d59-943a-40d9e717a0a1
id : 2
user : frjohn
group : farmers
action : put
transaction id : 41d412e2-1c1b-4d59-943a-40d9e717a0a1
label : Zoo
creation time : 2023-04-18 15:28:48
state : COMPLETE
warnings :
sub records ->
+ id : 2
sub_id : 8d457f6c-f26c-43db-98ff-7c2efe7ff695
state : COMPLETE
retries : 0
last update : 2023-04-18 15:28:53
In these last examples, the sub records are present as the NLDS will split
large transactions (with many files, or large files) into smaller units of work,
and create a sub record for each one of them.
Being able to easily check the progress of transactions in the NLDS is a key
design idea. To enable a program to check the progress, the -j option can
be used to return a JSON formatted version of the status.
Querying the file collections the user holds on the NLDS (LIST)
The put and putlist commands above create holdings in the NLDS
catalog. Holdings can be thought of as collections of transactions
which, in themselves, are collections of files Therefore, a holding
can also be thought of as a collection of files.
To see the holdings that are assigned to a user in NLDS, use the list
command. Invoke the list command on its own to see all of the holdings
that a user has:
> nlds list
Listing holdings for user:frjohn, group:farmers
id label ingest time
1 SheepPen 2023-04-18 15:21:37
2 Zoo 2023-04-18 15:28:48
(the user_name and group have not been specified with the -u and
-g arguments here, and so the defaults are read from the
Configuration File.)
This table shows the numeric id, label and latest ingest time for
the holding. To examine the holding in more detail, the -i option
can be used with the id, or the -l option can be used with the label.
> nlds list -l SheepPen
id : 1
label : SheepPen
ingest time : 2023-04-18 15:21:37
transaction id : ebb89e7d-5671-41f9-9f42-968fa69b0c87
tags : sheepdog : skye
> nlds list -i 2 -u frjohn -g farmers
id : 2
label : Zoo
ingest time : 2023-04-18 15:28:48
transaction id : 41d412e2-1c1b-4d59-943a-40d9e717a0a1
tags : zoo : Bristol
Finally, tags can be used to seach for a holding:
> nlds list -t sheepdog:skye
Listing holding for user:frjohn, group:farmers, tag:{'sheepdog': 'skye'}
id : 1
label : SheepPen
ingest time : 2023-04-18 15:21:37
transaction id : ebb89e7d-5671-41f9-9f42-968fa69b0c87
tags : sheepdog : skye
Querying the files the user holds on the NLDS (FIND)
To view which files the user holds in the NLDS, use the find command:
> nlds find
Listing files for holdings for user:frjohn, group:farmers
h-id h-label path size time
1 SheepPen /Users/frjohn/sheep.txt 49.0B 2023-04-18 15:21:37
2 Zoo /Users/frjohn/albatross.txt 96.0B 2023-04-18 15:28:48
2 Zoo /Users/frjohn/rabbit.txt 50.0B 2023-04-18 15:28:48
Warning : issuing the find command like this, with no filters, will
make an attempt to list all of a user’s files. When a user has many files in
the NLDS, this is likely to end in a gateway timeout, as the request will
take too long to process. It is much better to use the options to the find
command to limit the number of files that will be returned. This can be done
in a number of ways, which will be illustrated below.
To list the files in a holding, use -i with the holding id (h-id) or
-l with the holding label (h-label).
> nlds find -i 1
Listing files for holding for user:frjohn, group:farmers, holding_id:1
path : /Users/frjohn/sheep.txt
type : FILE
size : 49.0B
user uid : 0
group gid : 20
permissions : rw-r--r--
ingest time : 2023-04-18 15:21:37
storage location: OBJECT_STORAGE
> nlds find -l Zoo
Listing files for holding for user:frjohn, group:farmers, label:Zoo
h-id h-label path size time
2 Zoo /Users/frjohn/albatross.txt 96.0B 2023-04-18 15:28:48
2 Zoo /Users/frjohn/rabbit.txt 50.0B 2023-04-18 15:28:48
In the first example, only one file is returned, so the full details are shown.
To view the particular details of a file in the second example, the filepath
of the file can be used with the -p argument.
> nlds find -l Zoo -p /Users/frjohn/rabbit.txt
Listing files for holding for user:frjohn, group:farmers, label:Zoo
path : /Users/frjohn/rabbit.txt
type : FILE
size : 50.0B
user uid : 504
group gid : 20
permissions : rw-r--r--
ingest time : 2023-04-18 15:28:48
storage location: OBJECT_STORAGE
The filepath argument can be a regular expression:
> nlds find -l Zoo -p /Users/frjohn/a.*
Listing files for holding for user:frjohn, group:farmers, label:Zoo
path : /Users/frjohn/albatross.txt
type : FILE
size : 96.0B
user uid : 504
group gid : 20
permissions : rw-r--r--
ingest time : 2023-04-18 15:28:48
storage location: OBJECT_STORAGE
Finally, tags can be used to list files from holdings that contain those tags:
> nlds find -t zoo:Bristol
Listing files for holding for user:frjohn, group:farmers, tag:{'zoo': 'Bristol'}
h-id h-label path size time
2 Zoo /Users/frjohn/albatross.txt 96.0B 2023-04-18 15:28:48
2 Zoo /Users/frjohn/rabbit.txt 50.0B 2023-04-18 15:28:48
Retrieving a single file from the NLDS (GET)
After the put and putlist commands above, there are three files in
two holdings in the NLDS, which can be seen by issuing the find command.
> nlds find
Listing files for holdings for user:frjohn, group:farmers
h-id h-label path size time
1 SheepPen /Users/frjohn/sheep.txt 49.0B 2023-04-18 15:21:37
2 Zoo /Users/frjohn/albatross.txt 96.0B 2023-04-18 15:28:48
2 Zoo /Users/frjohn/rabbit.txt 50.0B 2023-04-18 15:28:48
NLDS supports ways five of retrieving these files, by using the get command
in conjunction with:
The full file path.
A regular expression that evaluates to more than one file path.
A holding id.
A holding label.
A holding tag.
By default the NLDS will try to retrieve the file to the original location
indicated by the path field above. If the user does not wish to overwrite
any file that might now have that filepath, or they do not have permission to
access that filepath, then the optional target directory can be specified with
the option -r <target_path>
1. To GET a file using the fully qualified filepath, and write it to the current directory, invoke the command:
> nlds get /Users/frjohn/sheep.txt -r ./
GETLIST transaction accepted for processing.
user : frjohn
group : farmers
action : getlist
job label : 14bc9846
transaction id : 14bc9846-9d45-440a-af6c-dfcb5cb9dcae
This will also recreate the directory structure in the current directory, i.e.
the file will be written to <current_directory>/Users/frjohn/sheep.txt.
Using this method of retrieval, no holding is specified. If more than one file with the filepath is held in the NLDS (in different holdings), then the latest ingested file will be returned. See 3. A holding id or 4. A holding label to guarantee that a specific file, ingested at a specific time is returned.
2. NLDS understands regular expressions (regex). This is a useful tool as it allows a user to get files depending on a pattern. One use case would be to get all of the files beneath a certain directory. To get files using regular expressions, use the command:
> nlds get "/Users/frjohn/.*" -r ./
GETLIST transaction accepted for processing.
user : frjohn
group : farmers
action : getlist
job label : 016ae5b7
transaction id : 016ae5b7-3b0d-485c-8812-7b3fa1b003de
(The Users/frjohn/.* has to be in "" so as to not confuse the shell, which
will see the * as a wildcard and try to expand it to all files and directories
in the current path. Enclosing it in "" prevents this.)
3. To ensure that the file at a filepath retrieved from the NLDS is a particular
version, ingested on a particular day, the holding id can be specified in the
get command using the option -i.
> nlds get -i 2 /Users/frjohn/albatross.txt -r ./
GETLIST transaction accepted for processing.
id : 2
user : frjohn
group : farmers
action : getlist
job label : fb130e43
transaction id : fb130e43-25a3-4cef-9eeb-b31e72a1f808
If the user attempts to get a file from a holding that does not contain it, then
an error will be returned when a stat command is used to check the status
of the transaction.
> nlds get -i 1 /Users/frjohn/albatross.txt
GETLIST transaction accepted for processing.
id : 1
user : frjohn
group : farmers
action : getlist
job label : 5842d371
transaction id : 5842d371-bf07-4ad4-a6ff-c46876a84ca6
> nlds stat -i 13
State of transaction for user:frjohn, group:farmers, id:13
id : 13
user : frjohn
group : farmers
action : getlist
transaction id : 5842d371-bf07-4ad4-a6ff-c46876a84ca6
label :
creation time : 2023-04-24 16:01:05
state : FAILED
warnings :
sub records ->
+ id : 13
sub_id : 85e36999-fc80-4784-acbd-dcc2c9977bbd
state : FAILED
retries : 6
last update : 2023-04-24 16:01:06
failed files ->
+ filepath : /Users/frjohn/albatross.txt
reason : File:/Users/frjohn/albatross.txt not found in holding:SheepPen for user:frjohn in group:farmers.
4. Similary to 3, a label can be used to fetch a particular file from a holding.
> nlds get -l SheepPen /Users/frjohn/sheep.txt -r ./
GETLIST transaction accepted for processing.
user : frjohn
group : farmers
action : getlist
job label : SheepPen
transaction id : b0544301-aadb-4f26-b2e0-b4643b0adfee
label : SheepPen
Again, specifying a label that doesn’t exist or a file that does not exist in the holding will return an error:
> nlds get -l sheeppen /Users/frjohn/sheep.txt -r ./
GETLIST transaction accepted for processing.
user : frjohn
group : farmers
action : getlist
job label : sheeppen
transaction id : c07dd223-88cb-41ec-a1e2-00f31c162116
label : sheeppen
> nlds stat -i 15
State of transaction for user:frjohn, group:farmers, id:15
id : 15
user : frjohn
group : farmers
action : getlist
transaction id : c07dd223-88cb-41ec-a1e2-00f31c162116
label :
creation time : 2023-04-24 16:11:03
state : FAILED
warnings :
sub records ->
+ id : 15
sub_id : 16759739-bc53-44be-b678-3999d0f7b76b
state : FAILED
retries : 0
last update : 2023-04-24 16:11:04
failed files ->
+ filepath : /Users/frjohn/sheep.txt
reason : Exception during callback: Could not find record of requested holding: label: sheeppen, id: None
5. Finally, a tag can be specified when retrieving files:
> nlds get -t sheepdog:skye /Users/frjohn/sheep.txt -r ./ GETLIST transaction accepted for processing. user : frjohn group : farmers action : getlist job label : 23db226f transaction id : 23db226f-d377-4511-8cc8-656b006c4f1e tags : sheepdog : skye
Retrieving a list of files from the NLDS (GETLIST)
Similarly to how the user can PUT a list of files to the NLDS, the user can also GET files specified as a list in a text file. As before, this filelist file must be in plain text format, with the path of a single file per line, for example:
/Users/frjohn/albatross.txt
/Users/frjohn/rabbit.txt
The command and response then becomes (where test_getlist is the name of the
above file). Here give the retrieval a job_label of getlisttest:
> nlds getlist test_list -r ./ -b getlisttest
GETLIST transaction accepted for processing.
user : frjohn
group : farmers
action : getlist
job label : getlisttest
transaction id : d83d8c2d-7ba8-4be8-b8dd-c643e4bfba49
The stat command can then be used to check on the progress of the retrieval.
> nlds stat -b getlisttest
State of transaction for user:frjohn, group:farmers
id : 18
user : frjohn
group : farmers
action : getlist
transaction id : d83d8c2d-7ba8-4be8-b8dd-c643e4bfba49
label :
creation time : 2023-04-25 14:34:37
state : COMPLETE
warnings :
sub records ->
+ id : 18
sub_id : 419d164a-119a-4e6e-b919-fef154902066
state : COMPLETE
retries : 0
last update : 2023-04-25 14:34:38
A holding id or label can be used in conjunction with getlist to make sure that the correct version of the filepaths in the filelist are retrieved.
> nlds getlist -i 2 test_list -r ./ -b getlist2
GETLIST transaction accepted for processing.
id : 2
user : frjohn
group : farmers
action : getlist
job label : getlist2
transaction id : 441065cb-fc14-4260-9661-2a3b163a5dce
However, if the filelist contains files that are not in the holding id, a different terminating state will be produced for the transaction. If the filelist now contains:
/Users/frjohn/albatross.txt
/Users/frjohn/rabbit.txt
/Users/frjohn/sheep.txt
and the command is issued:
> nlds getlist -i 1 test_list -r ./ -b getlist3
GETLIST transaction accepted for processing.
id : 2
user : frjohn
group : farmers
action : getlist
job label : getlist3
transaction id : c4c520a1-fd2b-42cd-9a36-32ba94f3b562
then the terminating state is COMPLETE_WITH_ERRORS because the
/Users/frjohn/sheep.txt is not a part of the Zoo holding:
> nlds stat -i 22
State of transaction for user:frjohn, group:farmers, id:22
id : 22
user : frjohn
group : farmers
action : getlist
transaction id : 0f1d711e-6227-4bd9-bd0b-d1b7ed47220f
label :
creation time : 2023-04-25 14:44:52
state : COMPLETE_WITH_ERRORS
warnings :
sub records ->
+ id : 22
sub_id : 4c38aab3-16ae-4c21-bce6-9171e15fc231
state : COMPLETE
retries : 0
last update : 2023-04-25 14:44:54
+ id : 23
sub_id : 668de6ae-7c0e-4763-82bc-ebf7135f4420
state : FAILED
retries : 6
last update : 2023-04-25 14:44:53
failed files ->
+ filepath : /Users/frjohn/sheep.txt
reason : File:/Users/frjohn/sheep.txt not found in holding:Zoo for user:frjohn in group:farmers.
Changing the label of a file collection (META)
The meta command allows the user to change the label of a holding or alter
the holding’s tags. Changing the label is particularly useful if an automatically,
seemingly random label has been assigned to the holding:
> nlds list
Listing holdings for user:frjohn, group:farmers
id label ingest time
1 SheepPen 2023-04-18 15:21:37
2 Zoo 2023-04-18 15:28:48
3 e4c00744 2023-04-25 15:07:18
Here the holding with id 3 has the automatically generated label of e4c00744.
This can be changed to something more rememberable by using the meta command
with the -L (for new label) option. To specify which holding to change the
label for the -i (holding id) or -l (existing label) options can be used.
> nlds meta -i 3 -L Farm
Changed metadata for holding for user:frjohn, group:farmers, holding_id:3
id : 3
old metadata:
label : e4c00744
tags : {}
new metadata:
label : Farm
tags : {}
> nlds meta -l Farm -L SmallHolding
Changed metadata for holding for user:frjohn, group:farmers, label:Farm
id : 3
old metadata:
label : Farm
tags : {}
new metadata:
label : SmallHolding
tags : {}