[OAI-implementers] Flow Control chunk size

[Simeon Warner]

Hi Ann,

On Fri, 2 Feb 2007, Ann Apps wrote:
> 1. Are there any guidelines on best practice for what to choose as a 
> chunk size? I guess this question is really asking what size of data 
> package is it reasonable to send over HTTP.

In the DLF sponsored OAI best practices work 
(http://oai-best.comm.nsdl.org/cgi-bin/wiki.pl?ResumptionTokens) we 
decided something around 1MB per response was best. This is big enough to 
be reasonably efficient for large transfers (reducing overhead of many 
small requests that may not use a persistent connection) and not too 
large for XML parsers.

> 2. Is it permissible to have a different chunk size for ListIdentifiers 
> and ListRecords? The former will be a much shorter response than the 
> latter. Also can one have a different chunk size for ListRecords in 
> different metadata formats?

This is certainly permissible, commonly done and indeed recommended by
the 1MB response size suggestion.

Cheers,
Simeon