Infinite I/O

Notes from our storage lab on write performance (Part II)

Posted by Sheryl Koenigsberg on Jan 30, 2017 3:40:00 PM

In our last post, we looked at how Infinio's offload capability of significantly reducing the read I/O load on storage can improve write performance.   

Now that you understand the power of offload with a server-side cache, let's see what kinds of improvement we can see from more of these HCIBench tests. On the same all-flash server SAN using HCIBench, but this time at a 4k block size, you can see the improvement to a 50/50, 70/30, and 100% read workload.  


blog image IOPS improvement

The results from the 50/50 read/write test are similar to what we saw in our last tests: just over 50% IOPS.  A 70/30 workload (HCIBench's OLTP benchmark) shows nearly double the IOPS, both reads and writes.

The benefit to writes is clearer when we break out the read I/O from the write I/O.  Below are the results from the same test, showing the substantial improvements not just to reads (as expected) but also to writes. 

blog image IOPS read-write bracket3

 

Finally, let's see what the impact is to response time.  They are similarly impressive: here are the improvements to latency from the same tests.

 blog image latency improvement

Again, the 100% read workload shows the biggest improvement: 70%.  But the mixed workloads see substantial benefit as well: the 50/50 workload with Infinio is 40% faster and the 70/30 workload is 55% faster.  And this is while also increasing IOPS as shown above.

To summarize, for a 50/50 workload, we increase IOPS by over 50% while decreasing latency by 40%.  For a 70/30 workload, we double IOPS and reduce latency by 55%. 

And remember, there is a significant benefit to adding a read-only cache to your environment rather than a read-write cache, if your I/O patterns support it: there's no danger of losing data.  With a read-only cache, there's never any unique data in cache, so there's no need for complex and space-inefficient replication and data protection schemes.

If you'd like to see more results from our performance labs, let us know.

Think you might see improvement in your environment?

 

Topics: Talking Tech