[SERVER-15153] MongoDB: Does Write Concern guarantee the write on primary plus atleast one secondary Created: 05/Sep/14 Updated: 08/Sep/14 Resolved: 08/Sep/14 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Replication |
| Affects Version/s: | 2.6.4 |
| Fix Version/s: | None |
| Type: | Question | Priority: | Major - P3 |
| Reporter: | Gopal Annasundaram | Assignee: | Ramon Fernandez Marina |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Participants: |
| Description |
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I'm getting push back from few team members in using MongoDB for a project because of the issues raised in the blog http://aphyr.com/posts/284-call-me-maybe-mongodb regarding write concern. Appreciate if someone can confirm if the issues are addressed in latest Mongo 2.6.4 release. On a parallel note, if I have a primary with 2 secondaries, is it possible to make sure one of the secondaries is a mirror of primary (meaning no data loss when I failed over) using tag set? |
| Comments |
| Comment by Ramon Fernandez Marina [ 08/Sep/14 ] |
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Hi gopal_a00, this post from Asya Kamsky provides a great rebuttal to the blog post referenced by your team members. In particular, the post discusses issues affecting MongoDB versions up to 2.4.3, which is over 16 months old, and were fixed in version 2.4.4. Since then, MongoDB has published 11 minor stable releases and one major stable release. The latest MongoDB stable release is 2.6.4, and is recommended for production systems. Regarding avoiding rollbacks, you can use w: "majority" Write Concern in your application. For the "mirror" case you describe, w : <tag set> is the way to go. See the documentation on Write Concern for more information. Note that the SERVER project is for reporting bugs or feature suggestions for the MongoDB server and tools. For MongoDB-related support discussion please post on the mongodb-user group or Stack Overflow with the mongodb tag. A question like this involving more discussion would be best posted on the mongodb-user group. Regards, |