Emergency

Search Results for: raid cache

L2 cache for MySQL

The idea to use SSD/Flash as a cache is not new, and there are different solutions for this, both OpenSource like L2ARC for ZFS and Flashcache from Facebook, and proprietary, like directCache from Fusion-io. They …


Looking for RAID Controller without Battery Learning problems ?

A lot have been written about Battery Learning Cycle problems and its impact to MySQL Performance. Here are couple of links (1,2). It is good to see though there are some controllers coming out which …


Setting up XFS on Hardware RAID — the simple edition

There are about a gazillion FAQs and HOWTOs out there that talk about XFS configuration, RAID IO alignment, and mount point options.  I wanted to try to put some of that information together in a …


Aligning IO on a hard disk RAID – the Benchmarks

In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we …


The perils of uniform hardware and RAID auto-learn cycles

Last night a customer had an emergency in selected machines on a large cluster of quite uniform database servers. Some of the servers were slowing down in a very puzzling way over a short time …


More on dangers of the caches

I wrote couple of weeks ago on dangers of bad cache design. Today I’ve been troubleshooting the production down case which had fair amount of issues related to how cache was used. The deal was …


FlashCache: tpcc workload with FusionIO card as cache

This run is very similar what I had on Intel SSD X25-M card, but now I use FusionIO 80GB SLC card. I chose this card as smallest available card (and therefore cheapest. On Dell.com you …


FlashCache: tpcc workload

This is my last post in series on FlashCache testing when the cache is placed on Intel SSD card. This time I am using tpcc-like workload with 1000 Warehouses ( that gives 100GB of data) …


FlashCache: more benchmarks

Previously I covered simple case with FlashCache, when data fits into cache partitions, now I am trying to test when data is bigger than cache. But before test setup let me address some concern (which …


FlashCache: first experiments

I wrote about FlashCache there, and since that I run couple benchmarks, to see what performance benefits we can expect. For initial tries I took sysbench oltp tests ( read-only and read-write) and case when …