Manage storage and tiering

Tiering splits hot data on fast local volumes from cold data in cheaper object storage. Tiger Cloud implements that as a high-performance tier plus a low-cost object storage tier:

• You use high-performance storage to store and query frequently accessed data.

• You use low-cost object storage to cut costs by migrating rarely used data from the high-performance storage. After you enable tiered storage, you then either create automated tiering policies or manually tier and untier data.

You can query the data on the object storage tier, but you cannot modify it. Make sure that you are not tiering data that needs to be actively modified.

For low-cost storage, Tiger Data charges for data tiered based on its original uncompressed size in the high-performance storage tier. There are no additional expenses, such as data transfer or compute.

High-performance storage tier

By default, Tiger Cloud stores your service data in the standard high-performance storage. This storage tier comes in the standard and enhanced types. Enhanced storage is available under the Enterprise pricing plan only.

Standard high-performance storage

This storage type gives you up to 16 TB of storage and is available under all pricing plans. You change the IOPS value to better suit your needs in Tiger Console:

1. Select your service

   In Tiger Console, select your service, then click Operations > Compute and storage.

   By default, the type of high-performance storage is set to Standard.

2. Select the IOPS value

   Select the IOPS value in the I/O boost dropdown:

   • Under the Performance pricing plan, IOPS is set to 3,000 - 5,000 autoscale and cannot be changed.
   • Under the Scale and Enterprise pricing plans, IOPS is set to 5,000 - 8,000 autoscale and can be upgraded to 16,000 IOPS.

   

   The autoscaled IOPS value depends on your provisioned storage and pricing plan:

   Storage size	Performance plan IOPS	Scale/Enterprise plan IOPS
   Under 500 GB	Up to 3,000	Up to 5,000
   500 GB – 1,000 GB	Up to 4,000	Up to 6,000
   1,000 GB – 1,500 GB	Up to 5,000	Up to 7,000
   Above 1,500 GB	Up to 5,000	Up to 8,000

3. Click Apply

Enhanced high-performance storage

Note

Enhanced high-performance storage is available on the Enterprise pricing plan.

This storage type gives you up to 64 TB and 32,000 IOPS, and is available under the Enterprise pricing plan.

To get enhanced storage:

1. Select your service

   In Tiger Console, select your service, then click Operations > Compute and storage.

2. Select Enhanced storage type

   Select Enhanced in the Storage type dropdown.

   

   Note

   The enhanced storage is currently not available in sa-east-1.

3. Select the IOPS value

   Select the IOPS value in the I/O boost dropdown.

   Select between 8,000, 16,000, 24,000, and 32,000 IOPS. The value that you can apply depends on the number of CPUs in your service. Tiger Console notifies you if your selected IOPS requires increasing the number of CPUs. To increase IOPS to 64,000, click Contact us and we will be in touch to confirm the details.

   
4. Click Apply

You change from enhanced storage to standard in the same way. If you are using over 16 TB of enhanced storage, changing back to standard is not available until you shrink your data to be under 16 TB. You can make changes to the storage type and I/O boost settings without any downtime. Wait at least 6 hours to attempt another change.

Low-cost object storage tier

Note

Low-cost tiered storage is available on Scale and Enterprise pricing plans.

You enable the low-cost object storage tier in Tiger Console and then tier the data with policies or manually.

Enable tiered storage

You enable tiered storage from the Overview tab in Tiger Console.

1. Select your service

   In Tiger Console, select the service to modify.

2. Enable tiered storage

   In Explorer, click Data Tiering > then click Enable tiered storage.

   

   Once enabled, you can proceed to tier data manually or set up tiering policies. When tiered storage is enabled, you see the amount of data in the tiered object storage.

Automate tiering with policies

A tiering policy automatically moves any chunks that only contain data older than the move_after threshold to the object storage tier. This works similarly to a data retention policy, but chunks are moved rather than deleted.

A tiering policy schedules a job that runs periodically to asynchronously migrate eligible chunks to object storage. Chunks are considered tiered once they appear in the timescaledb_osm.tiered_chunks view.

You can add tiering policies to hypertables, including continuous aggregates, via Console UI or an SQL editor.

Add a tiering policy

To add a tiering policy, connect to your service and call add_tiering_policy:

SELECT add_tiering_policy(hypertable REGCLASS, move_after INTERVAL, if_not_exists BOOL = false);

For example, to tier chunks that are more than three days old in the example hypertable:

SELECT add_tiering_policy('example', INTERVAL '3 days');

By default, a tiering policy runs hourly on your database. To change this interval, call alter_job.

Remove a tiering policy

To remove an existing tiering policy, call remove_tiering_policy:

SELECT remove_tiering_policy(hypertable REGCLASS, if_exists BOOL = false);

For example, to remove the tiering policy from the example hypertable:

SELECT remove_tiering_policy('example');

If you remove a tiering policy, the remaining scheduled chunks are not tiered. However, chunks in tiered storage are not untiered. You untier chunks manually to local storage.

Manually tier and untier chunks

If tiering policies do not meet your current needs, you can tier and untier chunks manually. To do so, connect to your service and run the queries below in the data mode, the SQL editor, or using psql.

Tier chunks

Tiering a chunk is an asynchronous process that schedules the chunk to be tiered. In the following example, you tier chunks older than three days in the example hypertable. You then list the tiered chunks.

1. Select old chunks

   Select all chunks in example that are older than three days:

   SELECT show_chunks('example', older_than => INTERVAL '3 days');

   This returns a list of chunks:

   _timescaledb_internal._hyper_1_1_chunk
   _timescaledb_internal._hyper_1_2_chunk

2. Tier each chunk

   SELECT tier_chunk('_timescaledb_internal._hyper_1_1_chunk');

   Repeat for all chunks you want to tier. Tiering a chunk schedules it for migration to the object storage tier, but the migration won’t happen immediately. Chunks are tiered one at a time to minimize database resource consumption. A chunk is marked as migrated and deleted from the standard storage only after it has been durably stored in the object storage tier. You can continue to query a chunk during migration.

3. View tiered chunks

   SELECT * FROM timescaledb_osm.tiered_chunks;

To see which chunks are scheduled for tiering either by policy or by a manual call, but have not yet been tiered:

SELECT * FROM timescaledb_osm.chunks_queued_for_tiering;

Untier chunks

To update data in a tiered chunk, move it back to the standard high-performance storage tier in Tiger Cloud. Untiering chunks is a synchronous process. Chunks are renamed when the data is untiered.

1. Check which chunks are tiered

   SELECT * FROM timescaledb_osm.tiered_chunks;

   Sample output:

    hypertable_schema | hypertable_name |    chunk_name    |      range_start       |       range_end
   -------------------+-----------------+------------------+------------------------+------------------------
   public            | sample          | _hyper_1_1_chunk | 2023-02-16 00:00:00+00 | 2023-02-23 00:00:00+00
   (1 row)

2. Call untier_chunk

   CALL untier_chunk('_hyper_1_1_chunk');

3. Verify the chunk details

   SELECT * FROM timescaledb_information.chunks;

   Sample output:

   -[ RECORD 1 ]----------+-------------------------
   hypertable_schema      | public
   hypertable_name        | sample
   chunk_schema           | _timescaledb_internal
   chunk_name             | _hyper_1_4_chunk
   primary_dimension      | ts
   primary_dimension_type | timestamp with time zone
   range_start            | 2023-02-16 00:00:00+00
   range_end              | 2020-03-23 00:00:00+00
   range_start_integer    |
   range_end_integer      |
   is_compressed          | f
   chunk_tablespace       |
   data_nodes             |

Drop tiered data

To drop tiered data, call DROP TABLE on the corresponding hypertable. This removes the hypertable and all its associated data from the high-performance and low-cost storage.

Disable tiering

Warning

Contact Tiger Data support if you are disabling tiering when moving from Scale to Performance pricing plan.

If you no longer want to use tiered storage for a particular hypertable, drop the associated metadata by calling disable_tiering.

1. Remove tiering policies

   Drop all tiering policies by calling remove_tiering_policy.

2. Check for tiered data

   Make sure that there is no tiered data associated with this hypertable:

   1. List the tiered chunks:

      SELECT * FROM timescaledb_osm.tiered_chunks;

   2. If you have any tiered chunks, either untier this data, or drop these chunks from tiered storage.

3. Disable tiering

   SELECT disable_tiering('my_hypertable_name');

4. Verify tiering is disabled

   SELECT * FROM timescaledb_osm.tiered_hypertables;