Setting the chunk size when downloading output

Question

When downloading output from SDL LiveContent, the GetNextDataObjectChunkByIshLngRef call takes a piSize parameter that specifies the "maximum number of bytes to be read from the object content". So if I want to download the entire output in one call, I can set piSize to the value of //@size returned in GetDataObjectInfoByIshLngRef . But how large does a output need to be before I should set it to a smaller value? Or does this depend entirely on the resources of the client?

Dave De Meyer · Accepted Answer

Correct, it truly depends on resources available, and actually to be more accurate the amount of free-memory within the server-side processes (so ISHWS IIS application pool in your scenario). Remember that server-side resources are shared with other users, hence load. So if you download a 100MB in one go, it can work, until there are 5 people doing that at the same time and then someone might get unlucky. 
 
Have a look on how it is implemented in the PowerShell library ISHRemote, see github.com/.../GetIshPublicationOutputData.cs where $ishSession.ChunkSize by default states 10485760 bytes.

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Setting the chunk size when downloading output