DevGrok

If you add an additional blank EBS volume to a CentOS 7 EC2 instance, it won’t auto-partition in the same way as the primary volume gets resized on launch. Additionally if your baking an image you will certainly encounter problems with it not automounting on different instance types and even manually trying to mount it can give misleading error messages.

If your unfortunate enough to still be using CentOS 6 in AWS than more than likely be stumped why the root partition isn’t resizing like most other distros you launch.

If you want to gather log files on your ECS hosts running a Amazon ECS-optimized AMI, then there’s instructions on how to install the Previous CloudWatch Logs Agent using cloud-init and some user data. The old Logs Agent is still supported but the new Unified CloudWatch Agent is recommended as it is touted to be faster but more importantly, allows easy collection of instance metrics. To install it, simply launch an EC2 instance using one of the Amazon ECS AMI ’s, and put this in the user-data section (expand the advanced configuration of the launch wizard). Once the EC2 instance is started up, just simply create an AMI from it, shutdown the EC2 instance and use this new AMI for you ECS clusters or for your Batch Compute Environments. With a bit of modification, this script could be used to install and configure it on the launch of each ECS instance, but having a pre-baked AMI is a bit cleaner. This script also increase the default docker container size to 100GB, using the ECS Age...

A while ago I posted a solution to OutOfMemoryError: unable to create new native thread , however I encountered a problem caused by the nproc setting but wasn't fixable by a simple ulimit command. The problem we were encountering was that we couldn't sudo into service account when we had all our application servers running. Our sysadmins have setup a user escalation script, which there's nothing wrong with. It does some prechecks, sudos a script under the requested user, does some logging, then does an exec <configured shell> . When there are too many processes, it manages to run the 2nd script as the user, however the exec command blocks, it never gets to the profile script to execute the ulimit command. I traced it down to the default soft limit for the number of process for all users to 1024. Our process count is way above that, which means when it tries to create a new process for bash when we run the sudo script, it can’t. So we are unable to sign into the a...