ource and window operator have no external state, and so in the commit phase, these operators don&rsquo;t have to take any action. The data sink does have external state, though, and commits the transaction with the external writes.</p>
<center>
<img src="/img/blog/eo-post-graphic-5.png" width="600px" alt="A sample Flink application - commit external state"/>
</center>
<p>So let&rsquo;s put all of these different pieces together:</p>
<ul>
<li>Once all of the operators complete their pre-commit, they issue a