Re: Confused about stream replication protocol documentation

[Bruce Momjian]

Patch applied to master, thanks.

---

On Thu, Dec 24, 2020 at 02:28:53AM +, Li Japin wrote:
> 
> On Dec 23, 2020, at 8:11 PM, Fujii Masao 
> wrote:
> 
> 
> On 2020/12/23 11:08, Li Japin wrote:
> 
> On Dec 22, 2020, at 11:13 PM, Fujii Masao <
> masao.fu...@oss.nttdata.com >
> wrote:
> 
> ‘B’ means a backend and ‘F’ means a frontend. Maybe as [1] does, 
> we
> should
> add the note like "Each is marked to indicate that it can be sent
> by
> a frontend (F) and a backend (B)" into the description about each
> message
> format for START_REPLICATION.
> 
> [1]
> 
> https://www.postgresql.org/docs/devel/protocol-message-formats.html
>   protocol-message-formats.html>
> 
> Thanks for your clarify.  Maybe we should move the "protocol message
> formats”
> before “stream replication protocol” or referenced it in "stream
> replication protocol”.
> 
> 
> I like the latter. And maybe it's better to reference to also
> "53.6. Message Data Types" there because the messages for
> START_REPLICATION use the message data types.
> 
> 
> Add reference about “protocol message types” and “protocol message formats”.
> 
> index 4899bacda7..5793936b42 100644
> --- a/doc/src/sgml/protocol.sgml
> +++ b/doc/src/sgml/protocol.sgml
> @@ -2069,8 +2069,9 @@ The commands accepted in replication mode are:
>   
> 
>   
> -  WAL data is sent as a series of CopyData messages.  (This allows
> -  other information to be intermixed; in particular the server can send
> +  WAL data is sent as a series of CopyData messages
> +  (See  and  "protocol-message-formats"/>).
> +  (This allows other information to be intermixed; in particular the
> server can send
>an ErrorResponse message if it encounters a failure after beginning
>to stream.)  The payload of each CopyData message from server to the
>client contains a message of one of the following formats:
> 
> --
> Best regards
> Japin Li
> 

> diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
> index 4899bacda7..5793936b42 100644
> --- a/doc/src/sgml/protocol.sgml
> +++ b/doc/src/sgml/protocol.sgml
> @@ -2069,8 +2069,9 @@ The commands accepted in replication mode are:
>   
>  
>   
> -  WAL data is sent as a series of CopyData messages.  (This allows
> -  other information to be intermixed; in particular the server can send
> +  WAL data is sent as a series of CopyData messages
> +  (See  and  linkend="protocol-message-formats"/>).
> +  (This allows other information to be intermixed; in particular the 
> server can send
>an ErrorResponse message if it encounters a failure after beginning
>to stream.)  The payload of each CopyData message from server to the
>client contains a message of one of the following formats:


-- 
  Bruce Momjian  https://momjian.us
  EDB  https://enterprisedb.com

  Only you can decide what is important to you.

Re: Confused about stream replication protocol documentation

[Li Japin]

On Dec 23, 2020, at 8:11 PM, Fujii Masao 
mailto:masao.fu...@oss.nttdata.com>> wrote:


On 2020/12/23 11:08, Li Japin wrote:
On Dec 22, 2020, at 11:13 PM, Fujii Masao 
mailto:masao.fu...@oss.nttdata.com> 
> wrote:

‘B’ means a backend and ‘F’ means a frontend. Maybe as [1] does, we should
add the note like "Each is marked to indicate that it can be sent by
a frontend (F) and a backend (B)" into the description about each message
format for START_REPLICATION.

[1]
https://www.postgresql.org/docs/devel/protocol-message-formats.html 

Thanks for your clarify.  Maybe we should move the "protocol message formats”
before “stream replication protocol” or referenced it in "stream replication 
protocol”.

I like the latter. And maybe it's better to reference to also
"53.6. Message Data Types" there because the messages for
START_REPLICATION use the message data types.

Add reference about “protocol message types” and “protocol message formats”.

index 4899bacda7..5793936b42 100644
--- a/doc/src/sgml/protocol.sgml
+++ b/doc/src/sgml/protocol.sgml
@@ -2069,8 +2069,9 @@ The commands accepted in replication mode are:
  

  
-  WAL data is sent as a series of CopyData messages.  (This allows
-  other information to be intermixed; in particular the server can send
+  WAL data is sent as a series of CopyData messages
+  (See  and ).
+  (This allows other information to be intermixed; in particular the 
server can send
   an ErrorResponse message if it encounters a failure after beginning
   to stream.)  The payload of each CopyData message from server to the
   client contains a message of one of the following formats:

--
Best regards
Japin Li



stream-replication-protocol-documentation.patch
Description: stream-replication-protocol-documentation.patch

Re: Confused about stream replication protocol documentation

[Fujii Masao]

On 2020/12/23 11:08, Li Japin wrote:



On Dec 22, 2020, at 11:13 PM, Fujii Masao mailto:masao.fu...@oss.nttdata.com>> wrote:

‘B’ means a backend and ‘F’ means a frontend. Maybe as [1] does, we should
add the note like "Each is marked to indicate that it can be sent by
a frontend (F) and a backend (B)" into the description about each message
format for START_REPLICATION.

[1]
https://www.postgresql.org/docs/devel/protocol-message-formats.html 



Thanks for your clarify.  Maybe we should move the "protocol message formats”
before “stream replication protocol” or referenced it in "stream replication 
protocol”.


I like the latter. And maybe it's better to reference to also
"53.6. Message Data Types" there because the messages for
START_REPLICATION use the message data types.

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

Re: Confused about stream replication protocol documentation

[Li Japin]

On Dec 22, 2020, at 11:13 PM, Fujii Masao 
mailto:masao.fu...@oss.nttdata.com>> wrote:

‘B’ means a backend and ‘F’ means a frontend. Maybe as [1] does, we should
add the note like "Each is marked to indicate that it can be sent by
a frontend (F) and a backend (B)" into the description about each message
format for START_REPLICATION.

[1]
https://www.postgresql.org/docs/devel/protocol-message-formats.html

Thanks for your clarify.  Maybe we should move the "protocol message formats”
before “stream replication protocol” or referenced it in "stream replication 
protocol”.

--
Best regards
Japin Li

Re: Confused about stream replication protocol documentation

[Fujii Masao]

On 2020/12/22 18:07, Li Japin wrote:

Hi, all

In Stream Replication Protocol [1], the documentation of `START_REPLICATION` 
message is

XLogData (B)
   …
Primary keepalive message (B)
   …
Standby status update (F)
   …
Hot Standby feedback message (F)
   ...

I’m confused about the means of ‘B’ and ‘F’? If it doesn't make sense, why we 
document here?
However, if it makes sense, should we explain it?
Can someone help me out?


‘B’ means a backend and ‘F’ means a frontend. Maybe as [1] does, we should
add the note like "Each is marked to indicate that it can be sent by
 a frontend (F) and a backend (B)" into the description about each message
 format for START_REPLICATION.

[1]
https://www.postgresql.org/docs/devel/protocol-message-formats.html

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

Confused about stream replication protocol documentation

[Li Japin]

Hi, all

In Stream Replication Protocol [1], the documentation of `START_REPLICATION` 
message is

XLogData (B)
  …
Primary keepalive message (B)
  …
Standby status update (F)
  …
Hot Standby feedback message (F)
  ...

I’m confused about the means of ‘B’ and ‘F’? If it doesn't make sense, why we 
document here?
However, if it makes sense, should we explain it?
Can someone help me out?

Anyway, thanks in advance!

[1] https://www.postgresql.org/docs/devel/protocol-replication.html

--
Best regards
Japin Li