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Comment by lanstin

1 day ago

I had very good results giving 1 SQL DB per go routine, so the accesses were serialized up front, on a very high volume (130K requests/second) service. Exact transactionality was not a product goal, and the SQLite was just to backup the in memory state. If we lost a little due to abend or something, that was ok (although for normal maintenance it caught SIGTERM and stopped the listen and then waited for in flight calls and then flushed the remaining changes to SQLite; then on startup it would read the SQLite into memory to populate before taking the listen; persistent storage across container runs, and never both reads and writes to the same file at the same time. (It also just closed the DB and opened a new one when it hit some limit of rows, so as not to fill the disk; the max size of the SQLite corresponded to the max size of the LRU map being served from in memory; then it just flipped A / B between "a full memory worth of data stored" and "the currently updating state." A lot easier than having to write out proto bufs to disk or whatever I would have done for transient (during restarts/maintenance) persistence.

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lanstin

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petcat  1 day ago

Woof. That sounds very complicated. If you need that kind of write concurrency, use an unlogged table in postgres [0]. Then you don't have to invent a whole sharded thing yourself.

[0] https://www.postgresql.org/docs/current/sql-createtable.html...

  • glzone1  13 hours ago

    Running postgresql is an order of magnitude more complicated than sqlite.

    130k tps even with unlogged is not always super easy especially if getting hit concurrently. Postgresql connection overhead alone can be pretty brutal if you are setting up and tearing down connections or have 1,000 writers etc.

    Postgresql generally requires good network connectivity. Folks doing sqlite distributed tend to have everything independent, you literally don't need to worry about connection / security / firewall / permissioning / internode escape or data leaking etc, can even have problems in local side networking and services can still serve.