Wiredtiger on github

[DH]

Hi,

What's the difference between wiredtiger on https://github.com/wiredtiger/wiredtiger and mongo/src/mongo/db/storage/wiredtiger?

Thanks,

DH

[jona...@findmeon.com]

IIRC the structure is this:

*  https://github.com/wiredtiger/wiredtiger 

WiredTiger main repo

* mongo/src/mongo/db/storage/wiredtiger

Mongodb integration for wiredtiger

* mongo/src/third_party/wiredtiger

pinned WiredTiger version used for the release

[Stephen Steneker]

On Saturday, 7 May 2016 15:29:06 UTC+10, DH wrote:

What’s the difference between wiredtiger on https://github.com/wiredtiger/wiredtiger and mongo/src/mongo/db/storage/wiredtiger?

Hi DH,

Jonathan is correct. To elaborate a bit further …

The WiredTiger GitHub repo (https://github.com/wiredtiger/wiredtiger) is the upstream source for the WiredTiger storage engine. WiredTiger can also be used as a standalone storage engine, but this does not include any of the MongoDB features (eg. query language, replication, sharding, …). Conversely, there are some features of the underlying WiredTiger storage engine that have not been exposed or tested with MongoDB yet.

The second source path you’ve mentioned (src/mongo/db/storage/wiredtiger) is the storage engine integration that enables WiredTiger to be used with MongoDB. This implements the required storage engine API calls to handle data exchange between the MongoDB query layer and the WiredTiger storage engine.

There’s a third path which is relevant in the MongoDB source tree: src/third_party/wiredtiger. This is an import of an upstream source version from the WiredTiger GitHub repo (the first link above) that has been extensively tested with that version of the MongoDB server. There may be dependencies between storage API changes and WiredTiger versions, and this also ensures consistent behaviour for a given MongoDB server release.

Regards,
Stephen

​