<story><title>Discovering Azure&apos;s unannounced breaking change with Cosmos DB</title><url>https://metrist.io/blog/how-we-found-azures-unannounced-breaking-change/</url></story><parent_chain><item><author>dagss</author><text>This rhymes with my overall impression of Cosmos. It took us a while to see through the smokescreen because when talking to Microsoft support and representatives it is the Best Thing Ever and they sound so confident about it. But it really is a beta demo product sold with an alpha premium price tag.&lt;p&gt;If your traffic pattern is exactly right, and you always scale traffic up and never ever down and do not have spikes, I guess it is probably OK. The main problem is the docs are (or, at least were 2 years ago) not clear about all the caveats and restrictions but pretend it is a generic database that just works. So one has to discover all the caveats oneself.&lt;p&gt;Microsoft thinks the exact workings of the partitioning is something that should work so well you don&amp;#x27;t need to know it in detail. But, if your usecase is slightly off you end up really needing to know. I know at least one team who routinely copy all their data from one Cosmos instance to another and switch over traffic to the copy just to get a partitioning reset; it is one thing to have to do it; another to discover in production yourself it has to be done with no prior warning..&lt;p&gt;Also: The ipython+portal+Cosmos security meltdown from 1 1&amp;#x2F;2 years ago alone should be reason to look elsewhere.&lt;p&gt;(No, not a competitor, just have spent way way way too much engineering time moving first on and then off Cosmos and yes I am bitter)</text></item></parent_chain><comment><author>maltalex</author><text>This matches my (fairly extensive) experience with CosmosDb. It’s truly an awfully engineered product.&lt;p&gt;I cannot comprehend what organizational process lead not only to its creation, but also to its continued existence.&lt;p&gt;Is existence is a constant reminder that the road to hell is paved with good intentions, and that you better do your due diligence before adopting any piece of tech that’s not easy to replace. Even if it comes with a pedigree.&lt;p&gt;I wrote up some of the horrors stories a while back on HN: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=29295871&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=29295871&lt;/a&gt;</text></comment>
<story><title>Discovering Azure&apos;s unannounced breaking change with Cosmos DB</title><url>https://metrist.io/blog/how-we-found-azures-unannounced-breaking-change/</url></story><parent_chain><item><author>dagss</author><text>This rhymes with my overall impression of Cosmos. It took us a while to see through the smokescreen because when talking to Microsoft support and representatives it is the Best Thing Ever and they sound so confident about it. But it really is a beta demo product sold with an alpha premium price tag.&lt;p&gt;If your traffic pattern is exactly right, and you always scale traffic up and never ever down and do not have spikes, I guess it is probably OK. The main problem is the docs are (or, at least were 2 years ago) not clear about all the caveats and restrictions but pretend it is a generic database that just works. So one has to discover all the caveats oneself.&lt;p&gt;Microsoft thinks the exact workings of the partitioning is something that should work so well you don&amp;#x27;t need to know it in detail. But, if your usecase is slightly off you end up really needing to know. I know at least one team who routinely copy all their data from one Cosmos instance to another and switch over traffic to the copy just to get a partitioning reset; it is one thing to have to do it; another to discover in production yourself it has to be done with no prior warning..&lt;p&gt;Also: The ipython+portal+Cosmos security meltdown from 1 1&amp;#x2F;2 years ago alone should be reason to look elsewhere.&lt;p&gt;(No, not a competitor, just have spent way way way too much engineering time moving first on and then off Cosmos and yes I am bitter)</text></item></parent_chain><comment><author>nobodyandproud</author><text>Is this analogous to NTFS?&lt;p&gt;For you young uns, back in the 1990s Microsoft was so convinced that NTFS made file fragmentation impossible that they didn’t provide a way to defrag for a very long time.</text></comment>