article thumbnail

Poor Disk Performance

Brendan Gregg

From these outputs I try to determine if the problem is: - **The workload**: High-latency disk I/O is commonly caused by the workload applied. Rotational disks have extra latency from head seeks for random I/O, and spin ups from the idle state. Note the sdb latencies range from 32 ms to over 2 seconds! Hit Ctrl-C to end.

article thumbnail

Poor Disk Performance

Brendan Gregg

From these outputs I try to determine if the problem is: - **The workload**: High-latency disk I/O is commonly caused by the workload applied. Rotational disks have extra latency from head seeks for random I/O, and spin ups from the idle state. The latencies here look like they are a mix of normal speed (~1.9 Hit Ctrl-C to end.

Insiders

Sign Up for our Newsletter

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Trending Sources

article thumbnail

Poor Disk Performance

Brendan Gregg

From these outputs I try to determine if the problem is: - **The workload**: High-latency disk I/O is commonly caused by the workload applied. Rotational disks have extra latency from head seeks for random I/O, and spin ups from the idle state. Note the sdb latencies range from 32 ms to over 2 seconds! Hit Ctrl-C to end.

article thumbnail

A thorough introduction to bpftrace

Brendan Gregg

For example, iostat(1), or a monitoring agent, may tell you your average disk latency, but not the distribution of this latency. For smaller environments, it can be of more use helping eliminate latency outliers. Block I/O latency as a histogram. This traces block I/O, and shows latency as a power-of-2 histogram.

Latency 68
article thumbnail

Comparisons of Proxies for MySQL

Percona

MySQL router, after the 2048 connection, could not serve anything more. Let us take a look also the latency: Here the situation starts to be a little bit more complicated. Let us take a look also the latency: Here the situation starts to be a little bit more complicated. That allows it to go a bit further. and ProxySQL 6.6k.

Games 120
article thumbnail

SQL Server I/O Basics Chapter #2

SQL Server According to Bob

The caching of data pages and grouping of log records helps remove much, if not all, of the command latency associated with a write operation. Action Description Manual Checkpoint – Target Specified I/O latency target set to ​​ the default ​​ of ​​ 20ms.

Servers 40