Lightning talk - Logging

A 5 minute lightning talk I gave to my colleagues at a&m impact internetdiensten.

Transcript

1. View Slide

2. Logging
   Logging is the cutting, skidding, on-site
   processing, and loading of trees or logs onto
   trucks or skeleton cars.
   

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3. But why should I?
   You want to know...
   ● What happened?
   ● When did it happen?
   ● Where did it happen? (and where didn't it?)
   ● Which steps were taken?
   ● And sometimes, actual input and output
   

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4. Okay, but how do I do this then?
   ● Inspiration: log4j (java)
   ○ PHP: log4php
   ○ Python: logging (In standard library!)
   ○ Ruby: log4r, logging
   include('Logger.php');
   $logger = Logger::getLogger("main");
   $logger->info("This is an informational message.");
   $logger->warn("I'm not feeling so good...");
   INFO - This is an informational message.
   WARN - I'm not feeling so good...
   

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5. Tips, tricks & pitfalls
   ● Use the various levels effectively
   ○ (WARN == INFO) == False
   ● Debugging should be OFF on production
   ● Be careful with big objects or method calls
   ○ $logger->debug("Doing something with object " .
   $this->nastyLongObjectLookup()); // *yawn* App hangs
   

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6. Tips, tricks & pitfalls (cont)
   ● Be clear and verbose
   ○ $logger->info("User logged in"); // Uhh.. who did?
   $logger->info("User " . $user->id . " logged in");
   ○ $logger->warn("Got unexpected responsecode from
   webservice"); // Which response code?
   $logger->warn("Got unexpected responsecode " .
   $response->code . " from websevice");
   $logger->debug("Response data was: " . $response-
   >data"); // Real programmers don't need debuggers ;)
   

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7. Tips, tricks & pitfalls (cont)
   ● grep, sed, awk, sort, uniq
   ● Critical/Exception?
   ○ Yes, log it, but
   more importantly....
   Sentry!!
   

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8. Now, go forth
   and log!
   Image credits
   Logging truck and bush taxi accident: Wikipedia uploader Amcaja
   The Sentry: Marvel Comics
   

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