[CDRO-7495] Add content to update ES to OS timeout values (#93)

Author: jsmith-cb

cloudbees-cd/es-to-os-migration/README.md

@@ -9,9 +9,14 @@ CloudBees has provided the [reporting-data-reindex.pl](reporting-data-reindex.pl
 
 > [!IMPORTANT]
 > As described in the [known issues of the data migration](https://docs.cloudbees.com/docs/cloudbees-cd/latest/troubleshooting/data-migration-es-to-os#data-migration-known-issues), the migration options provided by CloudBees have a timeout of `180 minutes` per index to avoid unexpected hangs.
-> In cases where an index contains a considerably large amount of data, and its migration does not complete within the timeout duration, the migration process fails.
+> In cases where an index contains a considerably large amount of data, and its migration does not complete within the timeout duration, the migration process fails with a `500 read timeout` error.
 >
-> This may result in having to split such indexes into multiple smaller indexes. If you encounter multiple timeout issues, contact CloudBees support.
+> The timeout duration can be increased by updating the following lines in the [reporting-data-reindex.pl](reporting-data-reindex.pl): 
+> * [L#376](https://github.com/cloudbees/cloudbees-examples/blob/master/cloudbees-cd/es-to-os-migration/reporting-data-reindex.pl#L376)
+> * [L#423](https://github.com/cloudbees/cloudbees-examples/blob/master/cloudbees-cd/es-to-os-migration/reporting-data-reindex.pl#L423)
+> * [L#472](https://github.com/cloudbees/cloudbees-examples/blob/master/cloudbees-cd/es-to-os-migration/reporting-data-reindex.pl#L472)
+> 
+> If this does not fix the issue, you may need to split indexes into multiple smaller indexes. If you encounter multiple timeout issues, contact CloudBees support.
 
 ## Dependencies
 This utility requires `cb-perl` to run, and is executable in any environment with a CloudBees CD/RO server or agent installation.