[GitHub] [flink] fhueske commented on a change in pull request #8330: [FLINK-12388][docs] Update the production readiness checklist

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fhueske commented on a change in pull request #8330: [FLINK-12388][docs] Update the production readiness checklist
URL: https://github.com/apache/flink/pull/8330#discussion_r282921904
 
 

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 File path: docs/ops/production_ready.md
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 @@ -22,79 +22,54 @@ specific language governing permissions and limitations
 under the License.
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+The production readiness checklist provides an overview of configuration options that should be carefully considered before bringing an Apache Flink job into production. 
+While the Flink community has attempted to provide sensible defaults for each configuration, it is important to review this list and ensure the options chosen are sufficient for your needs. 
+
 * ToC
 {:toc}
 
-## Production Readiness Checklist
-
-Purpose of this production readiness checklist is to provide a condensed overview of configuration options that are
-important and need **careful considerations** if you plan to bring your Flink job into **production**. For most of these options
-Flink provides out-of-the-box defaults to make usage and adoption of Flink easier. For many users and scenarios, those
-defaults are good starting points for development and completely sufficient for "one-shot" jobs. 
-
-However, once you are planning to bring a Flink application to production the requirements typically increase. For example,
-you want your job to be (re-)scalable and to have a good upgrade story for your job and new Flink versions.
-
-In the following, we present a collection of configuration options that you should check before your job goes into production.
-
-### Set maximum parallelism for operators explicitly
-
-Maximum parallelism is a configuration parameter that is newly introduced in Flink 1.2 and has important implications
-for the (re-)scalability of your Flink job. This parameter, which can be set on a per-job and/or per-operator granularity,
-determines the maximum parallelism to which you can scale operators. It is important to understand that (as of now) there
-is **no way to change** this parameter after your job has been started, except for restarting your job completely 
-from scratch (i.e. with a new state, and not from a previous checkpoint/savepoint). Even if Flink would provide some way
-to change maximum parallelism for existing savepoints in the future, you can already assume that for large states this is 
-likely a long running operation that you want to avoid. At this point, you might wonder why not just to use a very high
-value as default for this parameter. The reason behind this is that high maximum parallelism can have some impact on your
-application's performance and even state sizes, because Flink has to maintain certain metadata for its ability to rescale which
-can increase with the maximum parallelism. In general, you should choose a max parallelism that is high enough to fit your
-future needs in scalability, but keeping it as low as possible can give slightly better performance. In particular,
-a maximum parallelism higher that 128 will typically result in slightly bigger state snapshots from the keyed backends.
+### Set An Explicit Max Parallelism
 
-Notice that maximum parallelism must fulfill the following conditions:
+The max parallelism, set on a per-job and per-operator granularity, determines the maximum parallelism to which a stateful operator can scale.
+There is currently **no way to change** the maximum parallelism of an operator after a job has started without discarding that operators state. 
 
 Review comment:
   un-highlight "no way to change"? The other aspects have similar issues and are not highlighted.

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