Segment replication is an experimental feature. Therefore, we do not recommend the use of segment replication in a production environment. For updates on the progress of segment replication or if you want to leave feedback that could help improve the feature, see the [Segment replication issue](https://github.com/opensearch-project/OpenSearch/issues/2229).
There are several methods for enabling segment replication, depending on the install type. You will also need to set the replication strategy to `SEGMENT` when creating the index.
1. Enabling segment replication for an existing index requires [reindexing](https://github.com/opensearch-project/OpenSearch/issues/3685).
1. Rolling upgrades are currently not supported. Full cluster restarts are required when upgrading indexes using segment replication. [Issue 3881](https://github.com/opensearch-project/OpenSearch/issues/3881).
1. [Cross-cluster replication](https://github.com/opensearch-project/OpenSearch/issues/4090) does not currently use segment replication to copy between clusters.
1. Increased network congestion on primary shards. [Issue - Optimize network bandwidth on primary shards](https://github.com/opensearch-project/OpenSearch/issues/4245).
1. Shard allocation algorithms have not been updated to evenly spread primary shards across nodes.
1. Integration with remote-backed storage as the source of replication is [currently unsupported](https://github.com/opensearch-project/OpenSearch/issues/4448).
### Further resources regarding segment replication