Dtrace probes documentation

Started by Joshua Tolleyalmost 17 years ago5 messageshackers
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#1Joshua Tolley
eggyknap@gmail.com

The dtrace probes documentation [1] spells each probe name with dashes
("transaction-start", "transaction-commit", etc.). Yet as far as I can see,
dtrace only works if you spell the probe names with double underscores
("transaction__start", "transaction__commit", etc.). Why the discrepancy?
Obvious patch attached, in case this needs to be changed.

- Josh / eggyknap

1: http://www.postgresql.org/docs/8.4/static/dynamic-trace.html

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#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Joshua Tolley (#1)
Re: Dtrace probes documentation

Joshua Tolley <eggyknap@gmail.com> writes:

The dtrace probes documentation [1] spells each probe name with dashes
("transaction-start", "transaction-commit", etc.). Yet as far as I can see,
dtrace only works if you spell the probe names with double underscores
("transaction__start", "transaction__commit", etc.). Why the discrepancy?

Read 26.4.3 and .4. I don't know why they have this bizarre set of
conventions, but the single-hyphen version is the spelling
most visible to end users.

regards, tom lane

#3Joshua Tolley
eggyknap@gmail.com
In reply to: Tom Lane (#2)
Re: Dtrace probes documentation

On Thu, May 28, 2009 at 06:28:14PM -0400, Tom Lane wrote:

Joshua Tolley <eggyknap@gmail.com> writes:

The dtrace probes documentation [1] spells each probe name with dashes
("transaction-start", "transaction-commit", etc.). Yet as far as I can see,
dtrace only works if you spell the probe names with double underscores
("transaction__start", "transaction__commit", etc.). Why the discrepancy?

Read 26.4.3 and .4. I don't know why they have this bizarre set of
conventions, but the single-hyphen version is the spelling
most visible to end users.

I thought it might be something like that. I've been playing with SystemTap,
and found that only the double-underscore version works for ... well, anything.
See http://blog.endpoint.com/2009/05/postgresql-with-systemtap.html for
details. Perhaps it's worth noting in the documentation that SystemTap users
will need to use the double-underscore version?

- Josh / eggyknap

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: Joshua Tolley (#3)
Re: Dtrace probes documentation

Joshua Tolley <eggyknap@gmail.com> writes:

On Thu, May 28, 2009 at 06:28:14PM -0400, Tom Lane wrote:

Read 26.4.3 and .4. I don't know why they have this bizarre set of
conventions, but the single-hyphen version is the spelling
most visible to end users.

I thought it might be something like that. I've been playing with SystemTap,
and found that only the double-underscore version works for ... well, anything.
See http://blog.endpoint.com/2009/05/postgresql-with-systemtap.html for
details. Perhaps it's worth noting in the documentation that SystemTap users
will need to use the double-underscore version?

I think a better solution is to persuade the Systemtap guys that they
ought to accept the single-hyphen spelling. I've put in a request for
that, we'll see what they think ...

regards, tom lane

#5Frank Ch. Eigler
fche@redhat.com
In reply to: Tom Lane (#4)
Re: Dtrace probes documentation

Tom Lane <tgl@sss.pgh.pa.us> writes:

[...]

See http://blog.endpoint.com/2009/05/postgresql-with-systemtap.html for
details. Perhaps it's worth noting in the documentation that SystemTap users
will need to use the double-underscore version?

I think a better solution is to persuade the Systemtap guys that they
ought to accept the single-hyphen spelling. [...]

Will do: http://sourceware.org/PR10225.

- FChE