Thread

1. Streaming replication and message type header

   Fujii Masao <masao.fujii@gmail.com> — 2010-02-03T08:19:46Z

   On Tue, Jan 19, 2010 at 12:20 AM, Heikki Linnakangas
   <heikki.linnakangas@enterprisedb.com> wrote:
   > Tom Lane wrote:
   >> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
   >>> Simon Riggs wrote:
   >>>> Do we need a new record type for that, is there a handy record type to
   >>>> bounce from?
   >>
   >>> After starting streaming, slices of WAL are sent as CopyData messages.
   >>> The CopyData payload begins with an XLogRecPtr, followed by the WAL
   >>> data. That payload format needs to be extended with a 'message type'
   >>> field and a new message type for the timestamps need to be added.
   >>
   >> Whether or not anyone bothers with the timestamp message, I think adding
   >> a message type header is a Must Fix item.  A protocol with no provision
   >> for extension is certainly going to bite us in the rear before long.
   >
   > Agreed a message type header is a good idea, although we don't expect
   > streaming replication and the protocol to work across different major
   > versions anyway.
   
   The attached patch adds a message type header into the payload in
   CopyData message sent from walsender to walreceiver, to make the
   replication protocol more extensible.
   
   Regards,
   
   -- 
   Fujii Masao
   NIPPON TELEGRAPH AND TELEPHONE CORPORATION
   NTT Open Source Software Center
   

2. Re: Streaming replication and message type header

   Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> — 2010-02-03T09:47:39Z

   Fujii Masao wrote:
   > On Tue, Jan 19, 2010 at 12:20 AM, Heikki Linnakangas
   > <heikki.linnakangas@enterprisedb.com> wrote:
   >> Tom Lane wrote:
   >>> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
   >>>> Simon Riggs wrote:
   >>>>> Do we need a new record type for that, is there a handy record type to
   >>>>> bounce from?
   >>>> After starting streaming, slices of WAL are sent as CopyData messages.
   >>>> The CopyData payload begins with an XLogRecPtr, followed by the WAL
   >>>> data. That payload format needs to be extended with a 'message type'
   >>>> field and a new message type for the timestamps need to be added.
   >>> Whether or not anyone bothers with the timestamp message, I think adding
   >>> a message type header is a Must Fix item.  A protocol with no provision
   >>> for extension is certainly going to bite us in the rear before long.
   >> Agreed a message type header is a good idea, although we don't expect
   >> streaming replication and the protocol to work across different major
   >> versions anyway.
   > 
   > The attached patch adds a message type header into the payload in
   > CopyData message sent from walsender to walreceiver, to make the
   > replication protocol more extensible.
   
   Ok, commmitted.
   
   -- 
     Heikki Linnakangas
     EnterpriseDB   http://www.enterprisedb.com