Hey everyone, I’m dealing with a tricky situation and could really use some advice. Our AWS Aurora MySQL cluster keeps running into severe memory problems that are causing outages.
Basically what happens is the available memory will suddenly plummet from around 30GB down to practically nothing within just a few minutes. This causes the database instance to crash completely.
I’ve already ruled out a few things. Connection count stays normal during these incidents, so it’s not a connection flood. I also looked at slow queries but only found a handful of entries that showed up after the memory drop started, so those seem like symptoms not causes.
I’m not a database expert by any means, so I’m wondering what other areas I should investigate. Are there specific metrics or logs I should be monitoring? What are the common culprits for this kind of rapid memory consumption in Aurora MySQL? Any suggestions for troubleshooting approaches would be awesome.
I encountered a similar issue with Aurora MySQL, where erratic memory spikes led to instances crashing unexpectedly. In my case, it was vital to examine the execution plans of queries that were consuming excessive memory. The Performance Insights dashboard can be particularly useful for identifying such queries. Additionally, consider potential impacts from scheduled jobs or batch processes running concurrently with these spikes, as increased data volume might change their efficiency.
It’s also worth checking the engine logs for any memory allocation failures preceding the crashes, and enabling general logging could provide more insight into what’s occurring in those critical moments before memory usage drops.
I’ve dealt with this exact issue on Aurora MySQL. Memory exhaustion usually comes from places you don’t expect. First, check your sort_buffer_size and read_buffer_size in your parameter group. If they’re too high, each connection gets its own buffer. With concurrent operations, this multiplies fast and eats memory like crazy. Compare your settings to the defaults. Also look for stored procedures or functions processing big result sets. I had a reporting function that was loading entire tables into memory during peak hours - total memory killer. Check your CloudWatch metrics for database connections and freeable memory. You’ll see patterns if this happens regularly. Sometimes it’s automated processes you wouldn’t think are memory-heavy.
sounds like you might hav some queries causing issues, like temp tables or joins without indexes. check the InnoDB buffer pool metrics and look for memory leaks from app connections. also, if there are bulk imports running, they can consume a lot of memory if not set up right.