Instrumenting Ruby on Rails With Traceview

1

On
Building

:

Instrumen1ng
Ruby
with

TraceView
in
10
minutes

Peter
Lombardo

h$p://blog.gameface.in
h$p://www.appneta.com/blog

I’ve
been
a
Rubyist
and
Linux
addict
for
over
a
decade,
mainly

developing
in
Ruby
and
JavaScript
(as
well
as
PHP
and
Perl).
I’m
the

creator
of
numerous
soHware
tools
and
applicaIons,
most
recently

Password
Pusher,
a
Ruby
on
Rails
applicaIon
to
communicate

passwords
over
the
web
and
Gameface,
a
social
networking

plaLorm
for
gamers
using
Rails
3.

When
I’m
not
creaIng
my
own
applicaIons,
I
help
develop
and

maintain
the
infrastructure
at
OurStage
and
manage
the
Ruby

community
for
AppNeta.

Peter
Lombardo

“Gameface
was
created
to

showcase
games,

the
people
who
play
them,

and
the
characters
they
play”

TraceView
by
AppNeta
gives
a
unique

in-‐depth
view
into
requests
even
as

they
cross
hosts
and
soKware
stacks.

Installa1on
and
setup
of
TraceView
for

your
app
is
a
simple
two
step
process

that
can
be
done
in
10
minutes
or
less.

h$p://www.appneta.com/traceview
h$p://www.appneta.com/

TraceView
provides
deep
performance

monitoring
of
web
apps.

It
gives
insight
into
your
web
app

performance
such
as
this:

…and
a
per
request
drill-‐down
that
shows

you
the
niOy
griOy
detail
of
where
1me
is

spent
in
individual
requests

and
even
end-‐user
monitoring:

I
run
it
on
Gameface
and
PasswordPusher

-‐
it’s
essen1al
in
iden1fying
problem

areas,
performance
boOlenecks
and
poor

performing
code.
(Read:
Ac1onView)

Disclaimer:
I
authored
the
Ruby
instrumenta6on
for
Traceview
so
I

may
be
a
bit
biased.
…but
with
good
reason!

h$p://gameface.in
h$p://pwpush.com/

Installing
TraceView
consists
of
two
parts:

1)  installing
the
system
daemon
on

your
host,
and

2)  installing
the
Ruby
gem
in
your

applica1on

h$p://www.appneta.com/apm-‐datasheet

Why
a
system
daemon?

TraceView
uses
a
system
daemon
to
collect

instrumenta6on
from
sources
beyond

applica6on
code
such
as
host
metrics,

Apache
or
Resque.

The
system
daemon
is
installed
with

two
commands
that
can
be
pasted
into

your
shell.

An
account
speciﬁc
version
of
these

commands
is
available
in
your

TraceView
dashboard
once
you
create

an
account.

(Under
SeWngs;
App
Conﬁgura1on;
Trace
New
Hosts)

And
the
gem
for
your
applica1on

Gemﬁle
available
on
RubyGems:

h$ps://rubygems.org/gems/oboe

gem 'oboe' !

TraceView
func1ons
by
sampling
a

subset
of
all
requests
that
go
through

your
web
applica1on.

This
sample
rate
must
be
set
at
the

entry
point
of
requests
in
your

applica1on.

This
can
be
a
load
balancer,
Apache/
nginx
or
Ruby
itself.

Successive
hosts
and
soKware
stacks

that
requests
pass
through
will
act

appropriately
according
to
upstream

seWngs.!

Yes.

That
means
requests
can
be
traced

across
hosts,
so6ware
stacks,
even

track
internal
API
calls
via
HTTP/SOAP/
REST
which
make
for
spectacular

applicaEon
insight.

…But
that’s
another
post
for
another
Eme.

For
this
walkthrough
we’re
going
to

assume
that
you’re
running
a
Ruby
on

Rails
applica1on
with
Unicorn,
Thin,

Puma
or
any
other
Rack
based
Ruby

webserver.

To
instead
conﬁgure
Apache/nginx
as
the
entry
point,
see
here.

If
you
setup
Apache
or
nginx
as
your
entry

point
then
you
can
skip
this
part
enErely.

The

gem
will
take
it’s
tracing

instrucEons
from
upstream
automaEcally.

Oboe!

When
the

gem
is
installed
in
your

applica1on,
it
makes
available

!
!
which
is
a
nested
hash
of
conﬁgura1on

op1ons
that
aﬀect
how
your
applica1on
is

instrumented.

Oboe::Config !
Oboe!

Luckily,
the
defaults
are
very
smart
and

only
a
couple
ini1al
values
need
to
be

conﬁgured.

The
two
required
values
are:

Oboe::Config[:tracing_mode] = 'always' !
Oboe::config[:sample_rate] = 100000 # 10% of incoming requests !

These
values
enable
tracing

(:tracing_mode)
and
sets
the
sample
rate

to
10%
(:sample_rate).

The
sample_rate
is
calculated
by
the
value

out
of
one
million.

e.g.
300000
would
equal
a
30%
sample
rate
meaning
3
out

of
10
requests
would
be
sampled.

(For
low
traﬃc
sites,
you
may
want
to
set
these
values
higher.)!

These
values
are
usually
set
in
a
Rails

ini1alizer
for
Ruby
on
Rails.

See
the
OpEonal
Rails
IniEalizer
sec1on

on
this
page.

A
complete
list
of
all
conﬁgura1on

op1ons
for
is
here.!Oboe::Config !

And
that’s
it.
Now
to
the
good
stuﬀ…!

GeWng
Performance

Data

If
you
want
to
test
that
the
oboe
gem
is

func1onal,
start-‐up
a
Rails
console,
you

should
see
a
message
to
stdout

similar
to:

Tracelytics oboe gem 1.4.0.2 successfully loaded. !

Note
that
on
hosts
that
don’t
have
the
system

daemon
installed,
the
oboe
gem
disables
itself

and
outputs
a
message
to
that
fact:

Deploy/restart
your
applica1on
and
you
should

start
seeing
traces
show
up
in
your
TraceView

dashboard
aKer
a
couple
minutes.

Unsupported Tracelytics environment (no libs). Going No-op. !

Things
are
moving
fast
for
the
Ruby

language
instrumenta1on
in
TraceView.

We
support
tracing
of:

memcache-‐client,
memcached,

dalli,
mongo,

moped,
mongoid,

mongomapper,
cassandra,

Ac1veRecord
(postgres,
mysql,
mysql2)

…plus
more.

Most
recently
we
added
support
for

Rack
and
Resque
tracing.

For
a
full-‐list
of
supported
libraries,
see

this
ar1cle.!

Extras:

Some
Random
Chart
Porn

A
screenshot
that
I
sent
to
Linode
when

performance
unexpectedly
dropped:

Linode
migrated
my
VPS
to
a
lesser

u1lized
host
with
evident
results

(Thanks
Linode):

An
older
issue
that
Gameface
had
with

atrocious
rendering
1mes:

If
you
haven’t
tried
out
TraceView

yet,
give
it
a
run.

You
won’t
be
disappointed.

Note:
AppNeta
now
oﬀers
free
tracing
for
single

projects.
Check
it
out
on
their
pricing
page.

Instrumenting Ruby on Rails With Traceview

Recomendados

Recomendados

Más contenido relacionado

Último

Último (20)

Destacado

Destacado (20)

Instrumenting Ruby on Rails With Traceview