Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. How long does it take to read the time?

Speed 126

Speed Java AWS Virtualization 126

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. How long does it take to read the time?

Speed 40

Speed Java AWS Virtualization 40

SQL Performance

JUNE 21, 2019

For SQL Server 2008R – 2014, you could lower this threshold using trace flag 2371. While hardware such as intelligent SANs, Solid State Disk, and other advancements have helped speed things up, wasted space in index can translate to wasted space in the buffer pool as well as wasting more I/O. That can take a long time on larger tables.

Servers 49

Servers Azure Hardware Database 49

Brendan Gregg

SEPTEMBER 5, 2017

Linux has been adding tracing technologies over the years: kprobes (kernel dynamic tracing), uprobes (user-level dynamic tracing), tracepoints (static tracing), and perf_events (profiling and hardware counters). I also checked a task list from /sys/fs/cgroup, and saw it's in a docker cgroup.

Virtualization 76

Virtualization AWS Engineering Hardware 76