How to keep your recorder database size under control

I’m having the same issue, the recorder is not purging and mine is 70gb already.
I tried reducing the purge_keep_days to 5, calling the purge service and it has no effect. There’s still months of history.
I’m worried I’ll lose my energy long term stats.
Is there any trick I’m missing?
I’d be ok clearing the db if I could keep my long term statistics, the energy stats at least.
Any tips?

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same issue, need help too

I see the disk went to 100% full last night, and then back to 90%.
I’m starting to suspect that HA needs more free disk to complete the purge. Could that be the case?

Is there any standard approach to tackle this without losing all my (precious) long term stats?

I’m very glad to see the database getting some developer attention lately, and I remain hopeful that we’ll be seeing great things in the future. That said, I personally wouldn’t consider the HA database a good repository for anything “precious.” If it were up to me, I’d have put the long-term energy statistics in their own database, or maybe even export them to simple csv files. There are lots of other tools which are good at manipulating and analyzing statistics. Getting the data out of HA would be the first step.

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I updated the query, because I got unexpected results from rct’s query (like percentages over 100%).

SELECT
	entity_id,
	total_count,
	100 * total_count / SUM(total_count) OVER () AS perc_count,
	total_bytes,
	100 * total_bytes / SUM(total_bytes) OVER () AS perc_bytes,
	(total_count * 60 * 60) / (unixepoch() - least_update) AS count_per_hour,
	(total_bytes * 60 * 60) / (unixepoch() - least_update) AS bytes_per_hour,
	datetime(least_update, 'unixepoch', 'localtime') AS available_since
FROM
(
	SELECT
		S.entity_id,
		COUNT(1) AS total_count,
		SUM(LENGTH(shared_attrs)) AS total_bytes,
		MIN(last_updated_ts) AS least_update
	FROM
		state_attributes AS SA
	INNER JOIN
		states AS S
	ON
		(SA.attributes_id=S.attributes_id)
	GROUP BY
		S.entity_id
) AS A
ORDER BY
	7 DESC
2 Likes

You should always have 125% of the database size in temporary space available for temp tables, schema changes, rebuilds, repairs, optimize runs, etc. Anything less and you risk running out of space or the system failing in some way.

If you are running MySQL < 10.6.9 the query can take so long that it doesn’t purge (see this MariaDB bug report https://jira.mariadb.org/browse/MDEV-25020). There has also been an optimization in 2023.2.3 to reduce the purge time.

Finally if you are running MariaDB < 10.5.17 there are other known issues with purging / performance that will likely never get fixed in the 10.5 or below series.

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Thanks for the clear explanation!
I am on SQLite, btw. I’ll copy over the db to a proper pc and see if it cleans it overnight (after manually calling an purge run).

sqlite makes it a lot easier. If you get really stuck I can look through the DB and see if something is wrong with it.

contact details in Endless purge process with MariaDB 10.6.10 · Issue #87352 · home-assistant/core · GitHub

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If you copy it over, be sure to shut down HA first or you’ll probably end up with a partial copy.

  1. shutdown ha
  2. make sure the wal and shm files are cleaned up to verify its not still accessing the db
# ls -l home-assistant_v2.db*
-rwxr-xr-x    1 root     root     876187648 Feb 13 23:00 home-assistant_v2.db
-rwxr-xr-x    1 root     root         65536 Feb 13 23:00 home-assistant_v2.db-shm
-rwxr-xr-x    1 root     root      21980232 Feb 13 23:00 home-assistant_v2.db-wal
  1. Copy the db to your local
  2. vacuum it to recover space.
SQLite version 3.38.5 2022-05-06 15:25:27
Enter ".help" for usage hints.
sqlite> vacuum;
  1. Copy it back to your instance
  2. start HA
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That helped, thanks bdraco!
it trimmed 1/3 of the size. I’m at 44GB now.
I think it won’t be enough, I have 30GB free now so I’ll need to find a more aggressive way. Is there anything I can do to signal to the DB to mark more as trashed, and then repeat the trick of vacuum in a 2nd computer?

If you are looking for a quick fix, you could stop, download again, delete the contents of the states table, vaccum again, and put it back up, than restart. That will allow you to keep the stats and you’ll only loose shorter term history.

delete from states;

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Oh, that’s exactly what I need. I’m considering moving to MySQL to avoid this requirement of having twice the space available for the purge step. (Purge is vacuum, right?)

The vacuum only happens monthly Recorder - Home Assistant

Any database engine you pick should have 125% of the database size available for temp tables, rebuilds, etc to be safe. MySQL will not save you from that, and its usually not worth the price of admission unless you have a specific need as you are signing up to be the DBA for your instance.

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Here is the states query updated to 2023.4.x for SQLite.

The attributes and entity_id are deduplicated so they only are stored once now which makes the attributes bytes calculation misleading.

SELECT 
  COUNT(state_id) AS cnt, 
  COUNT(state_id) * 100 / (
    SELECT 
      COUNT(state_id) 
    FROM 
      states
  ) AS cnt_pct, 
  SUM(
    LENGTH(state_attributes.shared_attrs)
  ) AS bytes, 
  SUM(
    LENGTH(state_attributes.shared_attrs)
  ) * 100 / (
    SELECT 
      SUM(
        LENGTH(state_attributes.shared_attrs)
      ) 
    FROM 
      states
  ) AS bytes_pct, 
  states_meta.entity_id 
FROM 
  states 
LEFT JOIN state_attributes ON (states.attributes_id=state_attributes.attributes_id)
LEFT JOIN states_meta ON (states.metadata_id=states_meta.metadata_id)
GROUP BY 
  states.metadata_id 
ORDER BY 
  cnt DESC
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This didn’t work for me, I got the following error:

ERROR 1242 (21000): Subquery returns more than 1 row

same issue…

same issue

It looks like we have a solution here:

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Just the SQL

SELECT
  COUNT(*) AS cnt,
  COUNT(*) * 100 / (SELECT COUNT(*) FROM states) AS cnt_pct,
  states_meta.entity_id
FROM states
LEFT JOIN states_meta ON (states.metadata_id=states_meta.metadata_id)
GROUP BY entity_id
ORDER BY cnt DESC;

2 Likes

Really works. Thank you @crazyasyou