title: Long running process debug. Strace, brk
body: <p>I'm have Magento webshop, it run cron jobs to execute scheduled processes. One of them is product import. It's responsible for importing of products and assigning them to categories. According to sql state I can see this part was finished. After it tries to invalidate cache. For cache I'm trying to use memcache on tcp or redis on socket. For both options I have the same result.I use strace command to see what it's trying to do.</p>
  
  <pre><code>sudo strace -e trace=all -f -d -p 10319
  </code></pre>
  
  <p>It's output for last 2 hours is:</p>
  
  <pre><code>[wait(0x57f) = 10319]
  pid 10319 stopped, [SIGTRAP]
  brk(0x236ec000 [wait(0x57f) = 10319]
  pid 10319 stopped, [SIGTRAP]
  )                         = 0x236ec000
   [wait(0x57f) = 10319]
  pid 10319 stopped, [SIGTRAP]
  brk(0x2372c000 [wait(0x57f) = 10319]
  pid 10319 stopped, [SIGTRAP]
  )                         = 0x2372c000
   [wait(0x57f) = 10319]
  pid 10319 stopped, [SIGTRAP]
  brk(0x2376c000 [wait(0x57f) = 10319]
  pid 10319 stopped, [SIGTRAP]
  )                         = 0x2376c000
  </code></pre>
  
  <p>I know that brk is used to allocate memory. </p>
  
  <p>What other output can mean? What can be the reason of such behavior? Any ideas?</p>