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MongoDB vs. Amazon DocumentDB: MongoDB CTO Breaks It Down

15 points by saranshk 8y ago

StudentStuff 8y ago
After the horrendous time I've had with "modern" MongoDB losing my data repeatedly through 2018, I will never touch it again. Postgres handles loss of power, full disks, kill -9 and numerous other edge cases just fine, while MongoDB proceeds to corrupt its data and not fail gracefully. Even the redheaded stepchild of databases that is MSSQL goes into read only mode when you have a full disk, there is no excuse for Mongo corrupting itself when a disk is full.
- gnulinux 8y ago
  Not a formal criticism because we didn't investigate too much into this, but just last week our dev db instance run out of disk and postgres did some really suspicious things. We confirmed that on multiple occasions queries returned with success (because we have logs of success) but the db writes weren't persisted. So the software assumed data was written and continued on happy path, leaving the db in a bad state. Luckily this was only a dev machine and trivial to recover from, and granted out of disk is a fatal problem, but we were still upset.
  - StudentStuff 8y ago
    We've seen Postgres continue to operate like this until you run out of ram, not ideal IMO, but better than corrupting the existing database. Ideally Postgres would lift that whole "on full disk go read only" feature from MSSQL.
  - anarazel 8y ago
    Did you turn fsync off?
crb002 8y ago
Why would anyone back themselves into a corner with Mongo? Postgres has all relevant features, doesn't corrupt your data, and has the RDBMS features to fall back on when you need it.
miguelmota 8y ago
Always see posts with titles such as "Why We Moved From MongoDB to PostgreSQL" and rarely "Why We Moved From PostgreSQL to MongoDB". MongoDB is simply unreliable with data and struggles to scale. A few companies that have moved away from MongoDB: shippable, dzone, theguardian, olery, urban airship, bump, etsy, viber, shareaholic, videoamp, digidoc 1. http://blog.shippable.com/why-we-moved-from-nosql-mongodb-to-postgressql http://blog.shippable.com/why-we-moved-from-nosql-mongodb-to... 2. https://dzone.com/articles/why-we-moved-from-nosql-mongodb-to-postgresql https://dzone.com/articles/why-we-moved-from-nosql-mongodb-t... 3. https://www.theguardian.com/info/2018/nov/30/bye-bye-mongo-hello-postgres https://www.theguardian.com/info/2018/nov/30/bye-bye-mongo-h... 4. https://developer.olery.com/blog/goodbye-mongodb-hello-postgresql/ https://developer.olery.com/blog/goodbye-mongodb-hello-postg... 5. https://blog.schmichael.com/2011/11/05/failing-with-mongodb/ https://blog.schmichael.com/2011/11/05/failing-with-mongodb/ 6. http://devblog.bu.mp/post/40786226011/from-mongodb-to-riak-7138 http://devblog.bu.mp/post/40786226011/from-mongodb-to-riak-7... 7. https://mcfunley.com/why-mongodb-never-worked-out-at-etsy https://mcfunley.com/why-mongodb-never-worked-out-at-etsy 8. https://diginomica.com/2014/04/07/viber-migrates-mongodb-couchbase-halves-number-aws-servers/ https://diginomica.com/2014/04/07/viber-migrates-mongodb-cou... 9. https://www.shareaholic.com/blog/migrating-to-riak-at-shareaholic/ https://www.shareaholic.com/blog/migrating-to-riak-at-sharea... 10. https://www.linkedin.com/pulse/why-we-switched-from-mongo-postgres-dave-gullo https://www.linkedin.com/pulse/why-we-switched-from-mongo-po... 11. https://blog.svs.io/why-i-migrated-away-from-mongodb/ https://blog.svs.io/why-i-migrated-away-from-mongodb/ 12. https://pastebin.com/raw/FD3xe6Jt https://pastebin.com/raw/FD3xe6Jt
QuinnyPig 8y ago
MongoDB is completely appropriate for your production data. Not my production data--that stuff's important! But it's fine for yours...

15 points by saranshk 8y ago

After the horrendous time I've had with "modern" MongoDB losing my data repeatedly through 2018, I will never touch it again. Postgres handles loss of power, full disks, kill -9 and numerous other edge cases just fine, while MongoDB proceeds to corrupt its data and not fail gracefully. Even the redheaded stepchild of databases that is MSSQL goes into read only mode when you have a full disk, there is no excuse for Mongo corrupting itself when a disk is full.

gnulinux 8y ago
Not a formal criticism because we didn't investigate too much into this, but just last week our dev db instance run out of disk and postgres did some really suspicious things. We confirmed that on multiple occasions queries returned with success (because we have logs of success) but the db writes weren't persisted. So the software assumed data was written and continued on happy path, leaving the db in a bad state. Luckily this was only a dev machine and trivial to recover from, and granted out of disk is a fatal problem, but we were still upset.
- StudentStuff 8y ago
  We've seen Postgres continue to operate like this until you run out of ram, not ideal IMO, but better than corrupting the existing database. Ideally Postgres would lift that whole "on full disk go read only" feature from MSSQL.
- anarazel 8y ago
  Did you turn fsync off?

crb002 8y ago

Why would anyone back themselves into a corner with Mongo? Postgres has all relevant features, doesn't corrupt your data, and has the RDBMS features to fall back on when you need it.

miguelmota 8y ago

Always see posts with titles such as "Why We Moved From MongoDB to PostgreSQL" and rarely "Why We Moved From PostgreSQL to MongoDB". MongoDB is simply unreliable with data and struggles to scale. A few companies that have moved away from MongoDB: shippable, dzone, theguardian, olery, urban airship, bump, etsy, viber, shareaholic, videoamp, digidoc 1. http://blog.shippable.com/why-we-moved-from-nosql-mongodb-to-postgressql http://blog.shippable.com/why-we-moved-from-nosql-mongodb-to... 2. https://dzone.com/articles/why-we-moved-from-nosql-mongodb-to-postgresql https://dzone.com/articles/why-we-moved-from-nosql-mongodb-t... 3. https://www.theguardian.com/info/2018/nov/30/bye-bye-mongo-hello-postgres https://www.theguardian.com/info/2018/nov/30/bye-bye-mongo-h... 4. https://developer.olery.com/blog/goodbye-mongodb-hello-postgresql/ https://developer.olery.com/blog/goodbye-mongodb-hello-postg... 5. https://blog.schmichael.com/2011/11/05/failing-with-mongodb/ https://blog.schmichael.com/2011/11/05/failing-with-mongodb/ 6. http://devblog.bu.mp/post/40786226011/from-mongodb-to-riak-7138 http://devblog.bu.mp/post/40786226011/from-mongodb-to-riak-7... 7. https://mcfunley.com/why-mongodb-never-worked-out-at-etsy https://mcfunley.com/why-mongodb-never-worked-out-at-etsy 8. https://diginomica.com/2014/04/07/viber-migrates-mongodb-couchbase-halves-number-aws-servers/ https://diginomica.com/2014/04/07/viber-migrates-mongodb-cou... 9. https://www.shareaholic.com/blog/migrating-to-riak-at-shareaholic/ https://www.shareaholic.com/blog/migrating-to-riak-at-sharea... 10. https://www.linkedin.com/pulse/why-we-switched-from-mongo-postgres-dave-gullo https://www.linkedin.com/pulse/why-we-switched-from-mongo-po... 11. https://blog.svs.io/why-i-migrated-away-from-mongodb/ https://blog.svs.io/why-i-migrated-away-from-mongodb/ 12. https://pastebin.com/raw/FD3xe6Jt https://pastebin.com/raw/FD3xe6Jt

QuinnyPig 8y ago

MongoDB is completely appropriate for your production data. Not my production data--that stuff's important! But it's fine for yours...