External Memory Pressure In SQL Server 2019 On Linux

Anthony Nocentino walks us through memory pressure in SQL Server on Linux:

Now in SQL Server 2017 with that 7GB program running would cause Linux to need to make room in physical memory for this process. Linux does this by swapping least recently used pages from memory out to disk. So under external memory pressure, let’s look at the SQL Server process’ memory allocations according to Linux. In the output below we see we still have a VmSize of around 10GB, but our VmRSS value has decreased dramatically. In fact, our VmRSS is now only 2.95GB. VmSwap has increased to 5.44GB. Wow, that’s a huge portion of the SQL Server process swapped to disk.

In SQL Server 2019, there’s a different outcome! In the data below we see our 16GB VmSize which won’t change much because of the virtual address space for the process. With that large external process running SQL Server reduced VmRSS from 7.9GB (from Table 1) to 2.8GB only placing about 4.68GB in the swap file. That doesn’t sound much better, does it? I thought SQL Server was going to react to the external memory pressure…let’s keep digging and ask SQL Server what it thinks about this.

Anthony is doing some great work digging into this.  This is an area where you do have to understand the differences between Windows and Linux.

Related Posts

Merge Replication on Linux

Jignesh Raiyani shows how you can set up merge replication on SQL Server on Linux: In this article, we will discuss to deploy SQL Server Merge Replication on Linux environment. Many SQL Server features are not available on Linux by Microsoft but the Replication feature exists for Linux Environment Edition. Before starting anything, let’s address […]

Read More

Change Tracking in SQL Server

Tim Weigel covers the basics of change tracking in SQL Server: There aren’t a lot of parameters here. You can set change tracking on or off, you can specify your retention period, and you can specify whether to enable auto-cleanup or not. For the retention period, you have the choice of DAYS, HOURS, or MINUTES. […]

Read More

Categories

October 2018
MTWTFSS
« Sep Nov »
1234567
891011121314
15161718192021
22232425262728
293031