avro-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Doug Cutting <cutt...@apache.org>
Subject Re: schema backward compatibility in RPC?
Date Thu, 26 May 2011 09:18:02 GMT
Yes, this is intended to work.  The client and server perform a
handshake that ensures that each has the other's protocol.  Message
parameters are treated as a record.  So, in your example, the server
would ignore the date parameter.  If the server adds a parameter then it
should supply a default value to its version of the protocol to allow
for clients that do not supply this parameter.

Doug

On 05/24/2011 08:57 PM, Yang wrote:
> I remember that Avro can handle schema changes, for example: when I
> parse an incoming avro message, I can supply the known schema
> associated with this message,
> and the desired schema to parse it into.
> 
> 
> but I wonder if this ability is automatically available in RPC too?
> 
> for example , originally I define a remote call   echo() to be
> 
> echo ( message {
>                     date: integer,
>                     content: string,
>           }
>         )
> 
> 
> now the client still uses the old code, but server changes to
> 
> echo ( message {
>                     content: string
>            }
>      )
> 
> 
> would that still work?  if so, I wonder where the server gets the
> incoming schema?
> 
> Thanks  a lot
> Yang

Mime
View raw message