Just creating a couple new small volumes for a new SQL server's TempDB files. So I only need 2 20GB volumes but noiticed on pricing that:
General Purpose (SSD) - 500GB - 1500 / 3000IOPS = $51.70
Provisioned
IOPS (SSD) - 20GB - 1500 IOPS = $110.76
But something is telling me deep down that Provisioned IOPS must surely offer something more such as a guarentee yet general purpose gives you IOPS in the range of 1500 but based on how much strain the rest of the volumes are under? Else what's the point in using the smaller volume with provisioned IOPS?
Regards
Liam
For some applications, "predictable performance" is more important than "high performance", and PIOPS gives you both. One should always test, but for the case case you described, GP2 SSD really seems more efficient.
You can get even more out of GP2 combining volumes using RAID/LVM. For example, 1 1TB => 3K IOPS max, 2 x 500 GB => 6K IOPS max...
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When I start AWS node, and check average IOPS, it was usually between 3000-4000. But after running my test, when I check the iops in AWS node, I see it keeps on decreasing, impacting the throughput of my perfromance test.
Not sure if it is expected that iops will keep on dropping after sometime? Can anyone please guide here?
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Are you running GP2 or PIOPs?
If its GP2, it is worth noting that they use burstable credits allowing upto 3000 IOPs. After these credits expire you'll be left with 3 X EBS storage size (in GBs) for IOPs.
So for example, 50GB of storage would be 3 X 50 = 150 IOPs.
This article should help you to further understand: https://aws.amazon.com/blogs/aws/new-burst-balance-metric-for-ec2s-general-purpose-ssd-gp2-volumes/
Currently I have a RDS m4.2xlarge MySQL DB with 200GB of disk space allotted using general SSD, which gives me a limit of about 600 IOPS.
Looking at the monitoring I can see the most of the time the write IOPS are right at the 600 IOPS limit and can't go higher, then there are some short periods a lull followed by a burst over the 600 (I assume while my credits earned during the lull are burned). After the credits are used up it's back to the 600 limit.
My question is: is there are downside to running at the limit 99% of the time? My write queue depth is normally less than 2 and never really gets above 3.
Would I see any benefit buying provisioned IOPS (of say 1500) to handle the maximum peak requirements?
Currently I'm not really having any problems with the database, other than an occasional deadlock, but this seems to be expected for the amount of transactions going through the DB.
From the AWS documentation
Baseline I/O performance for General Purpose SSD storage is 3 IOPS for each GiB, with a minimum of 100 IOPS. This relationship means that larger volumes have better performance. For example, baseline performance for a 100-GiB volume is 300 IOPS. Baseline performance for a 1-TiB volume is 3,000 IOPS. And baseline performance for a 5.34-TiB volume is 16,000 IOPS.
In most cases the cheaper alternative is simply increase the disk space and get more IOPS allocated
When launching a new EC2 instance with EBS (especially the new C4 instance), which one is better? Assuming I need to provision 300 GB total.
1 single 300 GB EBS storage to get 900 IOPS (General Purpose SSD) or
3 EBS storage with 100 GB each and get 300 IOPS (General Purpose SSD) only for each storage?
Any idea?
Option 1 will give you faster performance and better reliability. With 3 EBS volumes you need to stripe them to make a single one and a failure on any of the three will result in a complete failure of all.
From the aws ec2 CALCULATOR(http://calculator.s3.amazonaws.com/index.html):
General purpose ssd
1000G storage,
3000 IOPS,
$97/month
Provisioned IOPS ssd
1000G storage,
3000 IOPS,
$320/month
My questions
If I attach 1000G General ssd to a ec2 instance, and used 100G, what IOPS I really get? 3000 or 300?
If question1 is 3000, in what conditions we should use provisioned IOPS ssd, while we can increase IOPS by adding storage at lower cost?
The baseline performance is 3 IOPS per GB of storage and can burst up to 3000 IOPS per volume. However the burst probably wont come into play. Since baseline for 1000GB volume is 3000 IOPS.
When you need more than 3000 IOPS. With provisioned you can get up to 30 IOPS per GB.
The instance size you attach these volumes to will also affect performance.
We have a replication setup on Amazon EC2 that used Magnetic disks (15GB) that we swapped with SSD disks (15GB) for each the replication servers. We noticed that the slaves would fall behind the master and never catch up with these new SSD disks. This is something that never happened with the Magnetic disks but happened on each and every SSD disk.
We decided to try and move the databases back to Magnetic disks after the SSD disks fell more than 2 days behind. Within 2 hours the slave completely caught up.
I thought that SSD disks were more efficient, and all around better than Magnetic disks and that is why Amazon decided to make them standard.
Another bit of information is that we are using Micro instances, but the only changes we made was with the attached disk.
Anyone have any ideas?
I think you might be bumping up against the max IOPS for your 15GB SSD drive.. Amazon only allows an average of 45 IOPS for that disk size. On a magnetic drive, they have an extra charge when you use more IOPS, it does not seem to be throttled in the same way:
From Amazon's Pop Up on IOPS:
The number of input-output operations per second. For Provisioned IOPS (SSD) volumes, you can specify the IOPS rate when you create the volume. The ratio of IOPS provisioned and the volume size requested can be a maximum of 30 (in other words, a volume with 3000 IOPS must be at least 100 GB). General Purpose (SSD) volume types have a baseline IOPS of volume size X 3 and can burst up to 3000 IOPS for 30 minutes.