Re: Reducing walreceiver latency with a latch

On 14/09/10 05:02, Fujii Masao wrote:
> +    /*
> +     * Walreceiver sets this latch every time new WAL has been received and
> +     * fsync'd to disk, allowing startup process to wait for new WAL to
> +     * arrive.
> +     */
> +    Latch        receivedLatch;
>
> I think that this latch should be available for other than walreceiver -
> startup process communication. For example, backend - startup process
> communication, which can be used for requesting a failover via SQL function
> by users in the future. What about putting the latch in XLogCtl instead of
> WalRcv and calling OwnLatch at the beginning of the startup process instead
> of RequestXLogStreaming?

Yes, good point. I updated the patch along those lines, attached.

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com