Hi Tanguy, On Thu, May 30, 2013 at 11:32 AM, Tanguy Moal <[email protected]> wrote:
> BTW, do you think data already stored using the original WebPage storage > class could be read using an alternative CustomWebPage if I only add new > fields *after* the existing and not modified ones ? (I use hbase as storage > backend) > > Really you want to be keeping to your avsc definition as much as possible. We expereinced this recently when we decided to add the batchId field to the avsc definition and there were some problems reported by users who had now upgraded to inject URLs, generate new batchId (which were subsequently stored in these new pages) and who them got loads of NPE because some tools were attempting to grab the batchId field for the legacy URLs which existed prior to the schema modification. This being said, if you are careful to make these checks within your code then I suppose you should be OK, hopefully over time the new field entries may gradually populate themselves throughout more and more of your URL entries but generally be prepared for some nasties if you change your WebPage schema willy nilly. It would be nice ot try though I suppose... if you have the patience ;0) Lewsi
