The above chart was included in last month’s SCI e-Newsletter and depicts recent Microsoft Exchange (2013) Solution Reviewed Program (ESRP) results for database access latencies. Storage systems new to this 5000 mailbox and over category include, Oracle, Pure and Tegile. As all of these systems are all flash arrays we are starting to see significant reductions in database access latencies and the #4 system (Nimble Storage) was a hybrid (disk and flash) array.
As you recall, ESRP reports on three database access latencies: read database, write database and log write. All three are shown above but we sort and rank this list based on database read activity alone.
Hard to see above, but reading the ESRP reports, one finds that the top 3 systems had 1.04, 1.06 and 1.07 milliseconds. average read database latencies. So the separation between the top 3 is less than 40 microseconds.
The top 3 database write access latencies were 1.75, 1.62 and 3.07 milliseconds, respectively. So if we were ranking the above on write response times Pure would have come in #1.
The top 3 log write access latencies were 0.67, 0.41 and 0.82 milliseconds and once again if we were ranking based on log response times Pure would be #1.
It’s unclear whether Exchange customers would want to deploy AFAs for their database and log files but these three ESRP reports and Nimble’s show that there should be no problem with the performance of AFAs in these environments.
What about data reduction?
Unclear to me is how much data reduction technologies played in the AFA and hybrid solution ESRP performance. Data reduction advantages would most likely show up in database IOPS counts more so than response times but if present, may still reduce access latencies, as there would be potentially less data to be transferred to-from the backend of the storage system into-out of storage system cache.
ESRP reports do not officially report on a vendor’s data reduction effectiveness, so we are left with whatever the vendor decides to say.
In that respect, Pure FlashArray//m20 indicated in their ESRP report that their “data reduction is significantly higher” than what they see normally (4:1) because Jetstress (ESRP benchmark program) generates lots of duplicated data.
I couldn’t find anything that Tegile T3800 or Nimble Storage said similar to the above, indicating how well their data reduction technologies worked in Jetstress as compared to normal. However, they did make a reference to their compression effectiveness in database size but I have found this number to be somewhat less effective as it historically showed the amount of over provisioning used by disk-only systems and for AFA’s and hybrid – storage, it’s unclear how much is data reduction effectiveness vs. over provisioning.
For example, Pure, Tegile and Nimble also reported a “database capacity utilization” of 4.2%, 60% and 74.8% respectively. And Nimble did report that over their entire customer base, Exchange data has on average, a 61.2% capacity savings.
So you tell me what was the effective data reduction for their Pure’s, Tegile’s and Nimble’s respective Jetstress runs? From my perspective Pure’s report of 4.2% looks about right (that says that actual database data fit in 4.2% of SSD storage for a ~23.8:1 reduction effectiveness for Jetstress/ESRP data. I find it harder to believe what Tegile and Nimble have indicated as it doesn’t seem to be as believable as they would imply a 1.7:1 and 1.33:1 reduction effectiveness for Jetstress/ESRP data.
Oracle FS1-2 doesn’t seem to have any data reduction capabilities and reported a 100% storage capacity used by Exchange database.
So that’s it, Jetstress uses “significantly reducible” data for some AFAs systems. But in the field the advantage of data reduction techniques are much less so.
I think it’s time that ESRP stopped using significantly reducible data in their Jetstress program and tried to more closely mimic real world data.
Want more?
The October 2016 and our other ESRP reports have much more information on Microsoft Exchange performance. Moreover, there’s a lot more performance information, covering email and other (OLTP and throughput intensive) block storage workloads, in our SAN Storage Buying Guide, available for purchase on our website. More information on file and block protocol/interface performance is also included in SCI’s SAN-NAS Buying Guide, also available from our website. And if your interested in file system performance please consider purchasing our NAS Buying Guide also available on our website.
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The complete ESRP performance report went out in SCI’s October 2016 Storage Intelligence e-newsletter. A copy of the report will be posted on our SCI dispatches (posts) page over the next quarter or so (if all goes well). However, you can get the latest storage performance analysis now and subscribe to future free SCI Storage Intelligence e-newsletters, by just using the signup form in the sidebar or you can subscribe here.
As always, we welcome any suggestions or comments on how to improve our ESRP performance reports or any of our other storage performance analyses.
The above chart was included in our e-newsletter Microsoft Exchange Solution Reviewed Program (ESRP) performance report, that went out at the end of July. ESRP reports on a number of metrics but one of the more popular is total (reads + writes) Exchange database transfers per second.
