On Wed, Sep 14, 2011 at 12:19, Adam Kocoloski <[email protected]>wrote:
> There's a multipart API which allows for a single PUT request containing > the document body as JSON and all its attachments in their raw form. > Documentation is pretty thin at the moment, and unfortunately I think it > doesn't quite allow for a pipe(). Would be really nice if it did, though. > It does. We figured it out together a couple weeks ago and that's when this code came into being. Requesting a _specific_ revision with ?revs=true will give you a multipart/related response suitable for passing straight into a ?new_edits=false&rev= PUT. See https://github.com/mikeal/replicate/blob/master/main.js#L49 > > On Wednesday, September 14, 2011 at 1:16 PM, Mikeal Rogers wrote: > > > npm is mostly attachments and I haven't seen any issues so far. > > > > I wish there was a better way to replicate attachments atomically for a > single revision but if there is, I don't know about it. > > > > It's probably a huge JSON operation and it sucks, but I don't have to > parse it in node.js, I just pipe() the body right along. > > > > -Mikeal > > > > On Sep 14, 2011, at September 14, 20118:42 AM, Adam Kocoloski wrote: > > > > > Hi Mikeal, I just took a quick peek at your code. It looks like you > handle attachments by inlining all of them into the JSON representation of > the document. Does that ever cause problems when dealing with the ~100 MB > attachments in the npm repo? > > > > > > I've certainly seen my fair share of problems with attachment > replication in CouchDB 1.0.x. I have a sneaking suspicion that there are > latent bugs related to incorrect determinations of Content-Length under > various compression scenarios. > > > > > > Adam > > > > > > On Tuesday, September 13, 2011 at 5:08 PM, Mikeal Rogers wrote: > > > > > > > My replicator is fairly young so I think calling it "reliable" might > be a little misleading. > > > > > > > > It does less, I don't ever attempt to cache the high watermark (last > seq written) and start over from there. If the process crashes just start > over from scratch. This can lead to a delay after restart but I find that > it's much simpler and more reliable on failure. > > > > > > > > It's also simpler because it doesn't have to content with being an > http client and a client of the internal couchdb erlang API. It just proxies > requests from one couch to another. > > > > > > > > While I'm sure there are bugs that I haven't found yet in it, I can > say that it replicates the npm repository quite well and I'm using it in > production. > > > > > > > > -Mikeal > > > > > > > > On Sep 13, 2011, at September 13, 201111:44 AM, Max Ogden wrote: > > > > > > > > > Hi Chris, > > > > > > > > > > From what I understand the current state of the replicator (as of > 1.1) is > > > > > that for certain types of collections of documents it can be > somewhat > > > > > fragile. In the case of the node.js package repository, > http://npmjs.org, > > > > > there are many relatively large (~100MB) documents that would > sometimes > > > > > throw errors or timeout during replication and crash the > replicator, at > > > > > which point the replicator would restart and attempt to pick up > where it > > > > > left off. I am not an expert in the internals of the replicator but > > > > > apparently the cumulative time required for the replicator to > repeatedly > > > > > crash and then subsequently relocate itself in _changes feed in the > case of > > > > > replicating the node package manager was making the built in couch > > > > > replicator unusable for the task. > > > > > > > > > > Two solutions exist that I know of. There is a new replicator in > trunk (not > > > > > to be confused with the _replicator db from 1.1 -- it is still > using the old > > > > > replicator algorithms) and there is also a more reliable replicator > written > > > > > in node.js https://github.com/mikeal/replicate that was was > written > > > > > specifically to replicate the node package repository between > hosting > > > > > providers. > > > > > > > > > > Additionally it may be useful if you could describe the > 'fingerprint' of > > > > > your documents a bit. How many documents are in the failing > databases? are > > > > > the documents large or small? do they have many attachments? how > large is > > > > > your _changes feed? > > > > > > > > > > Cheers, > > > > > > > > > > Max > > > > > > > > > > On Tue, Sep 13, 2011 at 11:22 AM, Chris Stockton > > > > > <[email protected] (mailto:[email protected] > )>wrote: > > > > > > > > > > > Hello, > > > > > > > > > > > > We now have about 150 dbs that are refusing to replicate with > random > > > > > > crashes, which provide really zero debug information. The error > is db > > > > > > not found, but I know its available. Does anyone know how can I > > > > > > trouble shoot this? Do we just have to many databases replicating > for > > > > > > couchdb to handle? 4000 is a small number for the massive > hardware > > > > > > these are running on. > > > > > > > > > > > > -Chris > > >
