3 ms·

Global write lock gone?

• s_kilk 12y ago
  It's down to a document-level lock with the new WiredTiger engine. http://www.mongodb.com/mongodb-3.0#performance http://www.mongodb.com/mongodb-3.0#performance
  • __Joker 12y ago
    WiredTiger is an optional engine. The default engine( the older one) is enhanced to collection level concurrency. If WT engine is better why they haven't at least made it default ? Is it for backward compatibility ?
    • s_kilk 12y ago
      My guess is to make upgrades easier. You can upgrade to the 3.0 binary without needing to migrate data to the new storage engine, which takes time. It wouldn't make sense from an ops standpoint to make an engine-migration mandatory.
      • drmirror 12y ago
        WiredTiger shows a lot of potential, but it would be irresponsible to make such a radically different engine the default for everyone, even for new databases, without giving it some time to mature.