I can help! :)
On 15 May 2013 16:23, Robert Newson <rnew...@apache.org> wrote: > :) > > Jan, I think you said you'd help start the IP clearance bit? > > On 15 May 2013 15:03, Noah Slater <nsla...@apache.org> wrote: > > PARTY TIME 🎉 > > > > > > On 15 May 2013 10:40, Robert Newson <rnew...@apache.org> wrote: > > > >> Thanks everyone. > >> > >> The tally is; > >> > >> 13 +1's > >> > >> The vote passes. We'll now move on to IP clearance. Once that's done > >> the work will arrive on a feature branch in our main git repository. > >> > >> B. > >> > >> > >> On 13 May 2013 04:31, Jason Smith <j...@iriscouch.com> wrote: > >> > Sorry, just catching up. > >> > > >> > +1 > >> > > >> > On Fri, May 10, 2013 at 4:29 PM, Jan Lehnardt <j...@apache.org> wrote: > >> >> +1 > >> >> > >> >> Jan > >> >> -- > >> >> > >> >> On May 7, 2013, at 21:34 , Robert Newson <rnew...@apache.org> wrote: > >> >> > >> >>> Hi All, > >> >>> > >> >>> I propose to merge in the following work, > >> >>> https://github.com/rnewson/couchdb/tree/nebraska-merge-candidate to > >> >>> the official Apache CouchDB repository to a new branch (i.e, *not* > >> >>> master). Once there, the full CouchDB developer community can begin > >> >>> the work to incorporate the code here into an official release. > >> >>> > >> >>> You do not need to respond if you are in agreement. If there is no > >> >>> response in 72 hours, I will assume lazy consensus. If we reach > >> >>> consensus, I will start the IP clearance process and then the merge. > >> >>> > >> >>> As most of you know, Paul Davis and I recently sequestered ourselves > >> >>> away from society (in a place called Nebraska) to make this merge > >> >>> happen. I want to clarify that this work is not the BigCouch code > you > >> >>> can see on github.com/cloudant/bigcouch but the Cloudant platform > from > >> >>> which BigCouch was made. This means it is bang up to date with all > the > >> >>> bug fixes and feature enhancements we've made in the last eighteen > >> >>> months or more. With that clarification made, here are our notes > about > >> >>> what we achieved, what it means to the project and what isn't yet > >> >>> done; > >> >>> > >> >>> Nebraska Merge Roundup > >> >>> > >> >>> > >> >>> Stats: > >> >>> > >> >>> > >> >>> 1402 - total new commits > >> >>> > >> >>> 312 - commits written during the merge (will be reduced > substantially > >> >>> by squashing) > >> >>> > >> >>> 408 - number of files changed > >> >>> > >> >>> 21,897 - number of lines added > >> >>> > >> >>> 4,277 - number of lines removed > >> >>> > >> >>> A retrospective: > >> >>> > >> >>> Bob Newson and I have come to the end of our merge sprint on getting > >> >>> BigCouch merged into Apache CouchDB. Its been a productive ten days > >> >>> here in the midwest. I managed to get Bob out to a bowling alley and > >> >>> he managed to get me to a sushi restaurant. In between the cultural > >> >>> exchanges we’ve also managed to get a significant amount of work > done > >> >>> on the merging as well. > >> >>> > >> >>> > >> >>> The current status of the merge is that we’ve managed to resolve the > >> >>> differences in the single node execution of CouchDB. Both the > >> >>> JavaScript and Erlang test suites run with only one failure in the > >> >>> Erlang test suite due to a (deliberately) missing constraint on the > >> >>> number of operating system processes. This should be a relatively > >> >>> straightforward fix but was not prioritized during our limited time > to > >> >>> work on the larger issues. > >> >>> > >> >>> > >> >>> We merged a large number of performance and stability enhancements > >> >>> back into single node CouchDB as well as a number of pure bug fixes. > >> >>> The biggest highlight is a brand new compactor that is both faster > and > >> >>> creates smaller and better organized post-compaction databases. > >> >>> > >> >>> > >> >>> The current status of the merge is that single node operations > should > >> >>> be completely unaffected as demonstrated by the test suite passing. > On > >> >>> the other hand we haven’t yet finished getting the clustered code > >> >>> merged to use some of the new changes in single node CouchDB. The > >> >>> single most significant portion of this work involves updates to the > >> >>> internal cluster API for views to use the recently rewritten indexer > >> >>> APIs. This should be a relatively straightforward bit of work that > >> >>> we’ll be finishing over the next few weeks. > >> >>> > >> >>> > >> >>> All in all the merge work done so far has been quite successful. > We’ve > >> >>> met our primary goal of getting the code merged in a fashion that > does > >> >>> not affect single node operation while providing a starting point > for > >> >>> the larger community to start reviewing the more significant changes > >> >>> made. Given the size of the diff between the two code bases we never > >> >>> expected to have a fully working clustered solution after ten days > of > >> >>> work but we have succeeded in providing a base of work that will > allow > >> >>> us and new contributors to get up to speed quickly. > >> >>> > >> >>> > >> >>> This work, coupled with work by Dave Cottlehuber and Benoît Chesneau > >> >>> on updating the build system and various other internal updates, > will > >> >>> provide a solid foundation for work going forward. Its an exciting > >> >>> time for CouchDB and anyone interested should keep an eye on the > next > >> >>> few releases as we ramp up work on various core aspects of the > >> >>> database. > >> >>> > >> >>> > >> >>> We’ve had an exciting few days working to prepare the road for an > >> >>> exciting next twelve to eighteen months. We hope that everyone will > >> >>> feel as excited as we do about the next twelve to eighteen months > for > >> >>> Apache CouchDB. It should be an exciting ride. > >> >>> > >> >>> > >> >>> > >> >>> Things we got done > >> >>> > >> >>> > >> >>> * Large update to the source tree layout for Erlang applications. > Each > >> >>> application now has a src/appname/(c_src|ebin|priv|src) structure. > The > >> >>> build system has been updated. > >> >>> > >> >>> * Renamed src/couchdb to src/couch to match the Erlang convention of > >> >>> the top directory name matching the Erlang application name. > >> >>> > >> >>> * Imported Cloudant Erlang applications for clustered CouchDB. These > >> >>> are imported with their history by using git subtree and merging the > >> >>> top level commit. These are not external deps, development will > happen > >> >>> within the CouchDB tree. The imported apps are: > >> >>> > >> >>> > >> >>> * config - A couch_config replacement (Behavior is mostly > identical > >> >>> to couch_config except how we listen for configuration changes > >> >>> internally to allow for smooth hot code upgrade). > >> >>> > >> >>> * twig - An rsyslog source replacement for couch_log. > >> >>> > >> >>> * rexi - An RPC library. Replaces Erlang’s built-in rex > application > >> >>> to avoid costly safety measures in the interest of performance and > >> >>> throughput. > >> >>> > >> >>> * mem3 - The “Dynamo” part of BigCouch responsible for managing > >> cluster state > >> >>> > >> >>> * fabric - The internal cluster-aware CouachDB API > >> >>> > >> >>> * ets_lru - A small library application that provides an LRU > >> >>> implementation using a couple ets tables. > >> >>> > >> >>> * ddoc_cache - Caches design documents on each node for use in > >> >>> design handler functions. This uses an ets_lru cache with a very > short > >> >>> TTL. > >> >>> > >> >>> * chttpd - The cluster aware HTTP layer > >> >>> > >> >>> > >> >>> Each imported app also had its build system updated to use Autotools > >> >>> along with the necessary updates noted above for the new application > >> >>> layouts for existing CouchDB erlang apps. > >> >>> > >> >>> > >> >>> * Merged a large amount of updates and fixes to couch_replicator > based > >> >>> on work done internally at Cloudant. Unfortunately due to an error > >> >>> when we created our internal clone we lost a bit of history in some > of > >> >>> the initial merge and have a big commit that affects > >> >>> couch_replicator_manager mostly. There are a number of other commits > >> >>> related to couch_replicator that resolve the single node vs. > clustered > >> >>> differences. Some noticeable couch_replicator features: > >> >>> > >> >>> > >> >>> * Optionally disable checkpoints so that replication can work when > >> >>> a source is read only. This should only be used for smaller > databases > >> >>> as each replication call has to scan the entire source database on > >> >>> each invocation. > >> >>> > >> >>> * A new changes_pending field in the _active_tasks output > >> >>> > >> >>> * A fix to the continuous replication to automatically reconnect > to > >> >>> a continuous changes feed when it sees a last_seq value. This allows > >> >>> for the source to selectively recycle the HTTP connections used > which > >> >>> can be quite useful for “permanent” replications. > >> >>> > >> >>> * A multitude of smaller bug fix and stability enhancements. > >> >>> > >> >>> > >> >>> Updates to single node couch: > >> >>> > >> >>> > >> >>> * We changed the by_seq tree to store a copy of the #full_doc_info{} > >> >>> record instead of the #doc_info{} record. This gives significant > speed > >> >>> improvements for compaction and replication and generally anything > >> >>> that needs to walk the by_seq tree and access document bodies > >> >>> internally. > >> >>> > >> >>> * We rewrote the compactor to be significantly faster as well as > >> >>> provides significantly better compacted databases. The two main > halves > >> >>> are to use a temp file and replace the use of btrees in the temp > file. > >> >>> The temp file only contains a temporary copy of the document ids. At > >> >>> the end of a compaction run we then rebuild the by_id btree in the > >> >>> compaction file from this temp file. The reason this helps so much > is > >> >>> that the compaction is based on the update_seq btree, which for most > >> >>> cases means that the id tree is updated in roughly random order > which > >> >>> is very bad for our append only btrees. By using the tmp file we can > >> >>> stream it in order back into the compacted db file at the end of > >> >>> compacting, generating a minimum amount of garbage in the process. > The > >> >>> other upgrade was to implement an external merge sort module > >> >>> (couch_emsort) that is used with this temporary file. > >> >>> > >> >>> * Reject updates to design docs that introduce updates that break > >> >>> compilation for source code. Currently we only check map and reduce > >> >>> calls as the other should provide user visible errors instead of > >> >>> inexplicably empty views. > >> >>> > >> >>> because my OCD kicked in and I was unable to resist. > >> >>> > >> >>> * Reverted a change made a long time ago that uses two file > >> >>> descriptors for each database. See the todo list. > >> >>> > >> >>> * The reason to remove the second fd is so that we can rewrite ref > >> >>> counting. Better ref counting makes everyone happy, but the real > >> >>> reason is for this next bullet point: > >> >>> > >> >>> * Optimize couch_server to not require a round trip message pass for > >> >>> opening a database that’s in the LRU. This is a significant > >> >>> performance boost for high concurrency access. We also optimized > >> >>> couch_server internals to not blow up when it’s under load. > >> >>> > >> >>> * Introduce a #leaf{} record into the revision trees. This is never > >> >>> written to disk but makes internal code a lot cleaner when dealing > >> >>> with multiple versions of rev tree values. > >> >>> > >> >>> * Some changes to couch_changes to enable clustered access. Also > some > >> >>> general cleanup > >> >>> > >> >>> * Internal changes to how CouchDB is booted in Erlang land. Not very > >> >>> sexy but this removes a lot of complicated un-Erlangy bits. We still > >> >>> have a bit of work left here. > >> >>> > >> >>> * btree chunk sizes are now configurable which can allow people to > >> >>> adjust the RAM/speed tradeoffs a bit more. > >> >>> > >> >>> * We now load update validation functions on the first write. This > is > >> >>> a cluster-motivated change because the clustered version of this > call > >> >>> is expensive and can lead to race conditions when opening a bunch of > >> >>> db shards simultaneously. This should be invisible to external > >> >>> clients. > >> >>> > >> >>> * Disabled conflict detection for local docs. They don’t replicate > so > >> >>> there’s no point. This just led to clusters getting stuck and > confused > >> >>> when there were lots of replications happening. > >> >>> > >> >>> * Changes to the multipart/mime parsing code. Necessary for > clustered > >> >>> attachment uploads to split the incoming data stream into N copies. > >> >>> > >> >>> * Don’t use init:restart/0 when reloading the ICU driver. I think > >> >>> this has a bug. But we should rewrite this driver to be a NIF > anyway. > >> >>> > >> >>> * New couch OS process manager. Significantly faster access to OS > >> >>> processes under heavy load. This replaces the hard limit with a soft > >> >>> limit. Process spawned over the soft limit will be used until > they’ve > >> >>> sat idle for a few minutes and then be closed. We have a todo item > to > >> >>> add the hard ceiling back in (while keeping the soft ceiling). > >> >>> > >> >>> * Automatically replace some easily identifiable JS reductions with > >> >>> their builtin counterparts. Uses a regex to do the detection so its > >> >>> not too smart. > >> >>> > >> >>> * Improved view updater write batch. > >> >>> > >> >>> * Updates to couchjs’ views.js to improve index update speeds > >> >>> > >> >>> * Updates to the _stats bultin reduce to allow reduces to work over > >> >>> emitted stats objects. Sometimes clients have summary data in a doc, > >> >>> and this allows them to combine stats if they follow the same > pattern > >> >>> as the builtin expects. > >> >>> > >> >>> * Added a config:reload() that is accessible by POST’ing to > >> >>> _config/_reload. Used by the JS tests to reset the config to what's > on > >> >>> disk. This should prevent those test run failures where a test fails > >> >>> leaving the config in a bad state causing all subsequent tests to > >> >>> fail. I think. Maybe. > >> >>> > >> >>> * Databases are deleted synchronously in the test suite. We may need > >> >>> to address this on Windows. But it does seem to reduce the number of > >> >>> “{error, file_exists}” failures. > >> >>> > >> >>> * I reimplemented the JS restartServer() function. There’s a new > >> >>> _restart/token URL that will given a unique value for each instance > of > >> >>> the Erlang VM. To run a restart we grab the current token value, hit > >> >>> _restart, then wait till we get a successful response with a > different > >> >>> token. This appears to have made the restart strategy more robust. > >> >>> > >> >>> > >> >>> > >> >>> Things that need doing > >> >>> > >> >>> > >> >>> IP Clearance - > >> >>> > >> >>> > >> >>> We’ll need to track down if we have the CCLA as well as look at each > >> >>> source file added to make sure each one is strictly from Cloudant or > >> >>> has an amenable license. I’m pretty sure that the only one of > interest > >> >>> is trunc_io.erl but we need to be thorough. > >> >>> > >> >>> documentation - > >> >>> > >> >>> > >> >>> There shouldn’t be much here since the entire point of this merge > was > >> >>> to not change the visible behavior of single node couch. A few > things > >> >>> to add about the testing endpoints. Maybe an update to the > compaction > >> >>> section mention the two new file names used. > >> >>> > >> >>> > >> >>> Copyright notices - > >> >>> > >> >>> > >> >>> We need to strip out copyright notices from individual files and > make > >> >>> sure all files have a standard Apache License v2 header. > >> >>> > >> >>> > >> >>> clustered vhosts - > >> >>> > >> >>> > >> >>> We’ve never implemented this at Cloudant. We either need to write a > >> >>> cluster or go back and tell people to use HAProxy (or similar) for > >> >>> such things. > >> >>> > >> >>> > >> >>> twig - > >> >>> > >> >>> > >> >>> We need to add another output type to twig that is configurable in > >> >>> some manner. Right now we spit out entire rsyslog records which > isn’t > >> >>> useful for most people. We’ll need to implement the file writer from > >> >>> couch_log as well as update the _log HTTP handler to know when it > can > >> >>> and can’t expect to find data on disk. > >> >>> > >> >>> > >> >>> fabric - > >> >>> > >> >>> > >> >>> This is going to need a lot of work. Specifically view access is > going > >> >>> to need to be updated to work with couch_mrview and friends. > >> >>> > >> >>> > >> >>> Boot a dev cluster - > >> >>> > >> >>> > >> >>> Once we fix up the clustering code we’ll need to write instructions > >> >>> and scripts for pulling up a dev cluster. > >> >>> > >> >>> > >> >>> OTP stuff - > >> >>> > >> >>> > >> >>> We’ve updated each app but we still need to pull some parts out of > >> >>> couchdb into their own application. Specifically the HTTP layer > needs > >> >>> its own app. We could probably pull out the os process/query_servers > >> >>> as well as the os daemons and friends. Once done we need to update > the > >> >>> supervision trees so we don’t have things like couch starting and > >> >>> managing the replication manager process. > >> >>> > >> >>> > >> >>> ddoc_cache - > >> >>> > >> >>> > >> >>> Wire this up in couch_httpd_db to actually be used. Right now its > only > >> >>> used in chttpd. > >> >>> > >> >>> > >> >>> couch_file upgrade - > >> >>> > >> >>> > >> >>> The revert to remove the second updater_fd from each #db{} record > >> >>> means that we’re back in the original position of files appearing to > >> >>> slow down significantly under load. Since the initial hammer > approach > >> >>> of just adding a second fd we’ve since discovered that the > underlying > >> >>> bug is due to the way that message passing works combined with > >> >>> Erlang’s file io. Significantly though is the fact that the fix is > >> >>> rather simple to implement. A first draft of this work is on an old > >> >>> branch of mine here: > >> >>> > >> >>> > >> >>> https://github.com/davisp/couchdb/commit/d856878 > >> >>> > >> >>> > >> >>> finish the size calculating changes - > >> >>> > >> >>> > >> >>> The #leaf{} record change is to enable us to add more data size > >> >>> calculations. CouchDB master calculates a data size that account for > >> >>> all bytes that are active in a .couch file. Cloudant is interested > in > >> >>> the total size of uncompressed docs and attachments minus the > internal > >> >>> overhead of btrees. And there’s a fourth number to calculate based > on > >> >>> the compression level used. Having each of these numbers will be > >> >>> useful as well as the calculations they’ll enable (ie, dead bytes in > >> >>> file, bytes used for overhead, compression ratio achieved, etc). > >> >>> > >> >>> > >> >>> couch_proc_manager - > >> >>> > >> >>> > >> >>> We need to implement the hard ceiling for capping the number of OS > >> >>> processes. We’ve started seeing a need for this at Cloudant with > some > >> >>> work loads so motivation to fix this is high. The only failing etap > is > >> >>> the assertion of this ceiling. > >> >>> > >> >>> > >> >>> Synchronous db delete on Windows - > >> >>> > >> >>> > >> >>> I did this because running the test suite was driving me bonkers. I > >> >>> need to ask Dave about how this behaves on Windows (my guess is not > >> >>> well) but I think we can close things up so that it works better > than > >> >>> the status quo. > >> >> > >> > > >> > > >> > > >> > -- > >> > Iris Couch > >> > > > > > > > > -- > > NS > -- NS
