This document discusses the tradeoffs between diagnosability and cloud computing. It notes that while the cloud aims to hide details, performance engineers need visibility into where time is spent to manage performance. It argues that instrumentation is key to diagnosing performance issues by marking tasks so their time can be identified and measured. The Oracle Database provides good tools for instrumentation, but applications also need to be designed to use them. Forethought about instrumentation can save costs and improve performance and availability.
1. Diagnosability
versus
The
Cloud
Cary
Millsap
Method
R
Corporation
cary.millsap@method-‐r.com
/
@CaryMillsap
OTN
Architect
Day,
Toronto
10:00a–10:30a
Thursday
21
April
2011
3. Q What
does
The
Cloud
mean
to
you?
Somebody
else’s
capital
expenditure.
Somebody
else’s
hardware.
Somebody
else’s
so8ware.
Somebody
else
backs
it
up.
Somebody
else
upgrades
it.
Somebody
else
fixes
it
when
it
breaks.
...
4. Q What
does
Diagnosability
mean
to
you?
You
can
find
problems
efficiently.
You
can
fix
problems
efficiently.
16. No
matter
how
your
software
fits
together,
to
manage
performance,
you
must
be
able
to
follow
how
time
flows
through
all
the
code
that
services
your
requests.
17. The
sequence
diagram
helps
you
conceptualize
time
flow...
http://en.wikipedia.org/wiki/File:Restaurant-‐UML-‐SEQ.gif
18. The
key
to
accounting
for
time
flow:
Instrumentation