There is a bug in the Advanced Reporting feature of Magento 2.2.6 that will cause the directory /tmp/analytics to grow to a suspiciously large size. In this article you will find more information about this and how to resolve this.
What is happening?
The Magento 2.2.6 bug that is mentioned above occurs when you have the Advanced Reporting feature enabled. The bug will cause the directory /tmp/analytics, which is used for the Advanced Reporting Service, to grow to such a large size it becomes blocking for the Hypernode. This can cause the shop to experience decreased availability because the rootdisk will fill up to maximal capacity, preventing mission critical services from being able to run.
Autohealing as a temporary solution
If this directory fills up and causes the shop to go down occasionally, our autohealing will eventually force a /tmp clean to rescue the node. This will temporarily solve the issue, until this bug causes the rootdisk to fill up again.
How to resolve this issue
Another temporary solution is to disable Advanced Reporting. This is specific to Magento 2.2.6 specific, so one might also want to consider upgrading your Magento to another version. You can find more information on this issue here.