| title | target-version |
|---|---|
housekeeping |
0.2.1 |
We provide Garbage Collection to purge tombstones and prevent the problem of documents growing.
However, when there are clients that has been editing old documents but have not been used for a long time, garbage collection becomes less efficient.
To solve this problem, we implement a housekeeping service that deactivates outdated clients.
Implement a housekeeping service that deactivates outdated clients.
If there are outdated clients, garbage collection becomes less efficient.
In this example, client c1 is outdated, the tombstone which has a
as its contents can not be purged because it is still being referenced by c1.
Agent periodically fetches outdated clients from the database. If the update times of clients are older than a certain threshold, the clients are candidates for deactivation.
In the deactivation process, the documents of the candidates are detached and
all synced_seqs of the clients removed from synced_seqs collection.
As a result, when calculating min_synced_seq to include in PushPull's
response, old synced_seq are removed so that relatively recently deleted
tombstones can be purged.
In the above example, client c1 is deactivated, the tombstone which has
a can be purged because it is not being referenced by c1.