<story><title>MongoDB and RocksDB at Parse</title><url>http://blog.parse.com/announcements/mongodb-rocksdb-parse/</url></story><parent_chain><item><author>lpsz</author><text>MongoDB seems to have a bad rep on HN for its various shortcomings, and yet here FB&amp;#x2F;Parse seem to use it. Is the bad rep overrated? (Honest question)</text></item></parent_chain><comment><author>Jweb_Guru</author><text>No, the bad reputation is not overrated.  This is the essence of why appeal to authority is a fallacy.  Facebook is (or was) largely written in PHP; that doesn&amp;#x27;t mean PHP&amp;#x27;s bad reputation is overrated.  Many banks run on COBOL; that doesn&amp;#x27;t mean Cobol&amp;#x27;s bad reputation is overrated.&lt;p&gt;MongoDB&amp;#x27;s bad reputation is well-deserved and based on a long history of misleading (or outright false) marketing claims coupled with poor technical properties (from unavoidable data loss to horrible compaction performance to global write locks).  At this point, even if all the known issues were fixed (and they aren&amp;#x27;t) it would still take a long time for their reputation to recover.  Given that some of MongoDB&amp;#x27;s direct competitors do &lt;i&gt;not&lt;/i&gt; suffer from these problems and can largely function as drop-in replacements, recommending people use something else is really the only responsible course of action.</text></comment>
<story><title>MongoDB and RocksDB at Parse</title><url>http://blog.parse.com/announcements/mongodb-rocksdb-parse/</url></story><parent_chain><item><author>lpsz</author><text>MongoDB seems to have a bad rep on HN for its various shortcomings, and yet here FB&amp;#x2F;Parse seem to use it. Is the bad rep overrated? (Honest question)</text></item></parent_chain><comment><author>htsh</author><text>Yes and no. Though I don&amp;#x27;t disagree with any of the criticisms or other comments at this level, for some of us MongoDB has been pretty good in production and we haven&amp;#x27;t experienced data loss. It all depends on your use case.&lt;p&gt;My first experience with it was for a social game running off of 3 mongo servers in a replica set &amp;amp; here at a large healthcare company we use it for several internal CRUD applications (again in 3-server replica sets) which we continue to iterate. In these use cases, Mongo&amp;#x27;s flexibility and ease of making changes trumped it&amp;#x27;s shortcomings. My understanding is that many social games still use Mongo to store player data as our studio was told to use it by a large publisher.&lt;p&gt;My take is that it&amp;#x27;s good for building prototypes and it&amp;#x27;s pretty flexible to both change &amp;amp; migrate data in and out &amp;amp; Javascript devs pick it up relatively quickly. But I also think one should be well aware of it&amp;#x27;s shortcomings and be careful not to use it where those things are of importance. More often than anything else, I recommend PostgreSQL when other people ask for a general-use db but I&amp;#x27;d likely would pick up Mongo myself simply for speed of development.&lt;p&gt;Lastly, being part of the &amp;quot;MEAN stack,&amp;quot; we can point junior devs &amp;amp; interns to one of the many books that cover the stack &amp;amp; they can learn best practices get up to speed quickly.  There&amp;#x27;s an advantage to having books &amp;amp; a slew of SO answers to refer to in that other devs aren&amp;#x27;t pulled off of their work to teach. We literally had interns committing code on Day 1 of their jobs last summer as they came in having read up on our stack.&lt;p&gt;Regarding claims MongoDB has made, which I&amp;#x27;ve only been made aware of the last two days, I don&amp;#x27;t think there&amp;#x27;s any defending that &amp;amp; it makes my itch to checkout rethinkdb a bit stronger than it was 2 days ago.</text></comment>