Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

    The web server handles all logging in terms of access and error logging for most CGI scripts.


    If your using DBI the database logs all data with greater efficiency than a hand rolled solution.


    Do you think in these instances logging is therefore unecessary?

Depends on whether what gets logged is what needs to be, I guess. :-) In general, I'd say no. These logs describe what happens at an interface, and misuse of an interface isn't necessarily the same as assumptions being violated. When it is, its signature can be quite unhelpful.

For example, maybe I'm updating a database through DBI, based on a key built from several bits of data. I pull these different bits out from the input record with regular expression captures, cat them all together (somehow) to build the key, and then do a $sth->execute or similar. Seems reasonable, right?

If one of my regex matches fails -- maybe the input data are corrupt, or one of the upstream programmers changed the record format slightly, or something -- the best I'm likely to do is get a "use of uninitialized value, line 666" warning from perl. I'll build a nonsense key, then try updating on it -- and updating on a key that doesn't exist isn't an error, last I checked, just a null op. Now maybe that warning makes sense to me, but if I'm catting three different strings together, any (or all) of which might be the problem, it's going to take a lot of unnecessary effort to track down the problem.

If, on the other hand, I do something like:

my ($key_part) = ($record =~ /$foo/) or warn "***WARNING: input record <$record> doesn't match $foo\n";

then I know exactly what's wrong, and how it's wrong, just from looking at the logs.

To me, that's a big win.

F o x t r o t U n i f o r m
Found a typo in this node? /msg me

In reply to Re(2): Defensive Programming and Audit Trails by FoxtrotUniform
in thread Defensive Programming and Audit Trails by FoxtrotUniform

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?

What's my password?
Create A New User
Domain Nodelet?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others meditating upon the Monastery: (2)
As of 2021-09-27 00:42 GMT
Find Nodes?
    Voting Booth?

    No recent polls found