# Redis Enterprise Software release notes 6.4.2-69 (May 2023)

```json metadata
{
  "schema_version": 2,
  "title": "Redis Enterprise Software release notes 6.4.2-69 (May 2023)",
  "description": "Amazon Linux 2 support. Configure envoy ports using rladmin. Added option to avoid specific nodes when using the optimized shards placement API. Added failure_detection_sensitivity to replace watchdog_profile.",
  "categories": ["docs","operate","rs"],
  "tableOfContents": {"sections":[{"id":"new-features-and-enhancements","title":"New features and enhancements"},{"children":[{"id":"deprecations","title":"Deprecations"}],"id":"version-changes","title":"Version changes"},{"id":"resolved-issues","title":"Resolved issues"},{"children":[{"id":"feature-limitations","title":"Feature limitations"},{"id":"operating-system-limitations","title":"Operating system limitations"}],"id":"known-limitations","title":"Known limitations"}]}

,
  "codeExamples": []
}
```


This is a maintenance release for ​[​Redis Enterprise Software version 6.4.2](https://redis.io/downloads/#software).

The following table shows the MD5 checksums for the available packages:

| Package | MD5 checksum (6.4.2-69 May release) |
|---------|---------------------------------------|
| Ubuntu 16 | 31631248672de0154ec20aee0bff9adc |
| Ubuntu 18 | 7d9ebd4ea5a23137d2bb3928134ea6ef |
| Ubuntu 20 | 357ceda7467fd66962f3cb5aa143def7 |
| RedHat Enterprise Linux (RHEL) 7<br/>Oracle Enterprise Linux (OL) 7 | 4d53fcce8c80910a05ed37ab64b57a7a |
| RedHat Enterprise Linux (RHEL) 8<br/>Oracle Enterprise Linux (OL) 8 <br/>Rocky Enterprise Linux | 88dc6a4d96b948b086f785dc42786d03 |
| Amazon Linux 2 | 7ed06bc0b35494e4a5c084528d6e8b9f |

## New features and enhancements

- Amazon Linux 2 support

- Enhanced installation logs (RS69079, RS69571, RS77857, RS89760)

- Added support for `rladmin` envoy port configuration (RS95483)

- Support the option to avoid specific nodes when using optimized shards placement API  (RS98795)

- Check port availability before installation and upgrade (RS80815)

- Added `failure_detection_sensitivity` policy to [cluster policy REST API requests](https://redis.io/docs/latest/operate/rs/references/rest-api/requests/cluster/policy). See the [`watchdog_profile` deprecation notice](#watchdog_profile) for more details.

#### Redis Stack v6.2.6

Redis Enterprise Software v6.4.2 includes the new features delivered in the latest [Redis Stack release (6.2.6 v6)](https://redis.com/blog/introducing-redis-stack-6-2-6-and-7-0-6/):

- [RediSearch v2.6.6](https://redis.io/docs/latest/operate/oss_and_stack/stack-with-enterprise/search)

- [RedisJSON v2.4.7](https://redis.io/docs/latest/operate/oss_and_stack/stack-with-enterprise/json)

- [RedisBloom v2.4.5](https://redis.io/docs/latest/operate/oss_and_stack/stack-with-enterprise/bloom)

- [RedisGraph v2.10.9](https://redis.io/docs/latest/operate/oss_and_stack/stack-with-enterprise/deprecated-features/graph)

- [RedisTimeSeries v1.8.9](https://redis.io/docs/latest/operate/oss_and_stack/stack-with-enterprise/timeseries)

See [Upgrade modules](https://redis.io/docs/latest/operate/rs/installing-upgrading/modules/upgrade-module) to learn how to upgrade a module for a database.

## Version changes

### Deprecations

#### watchdog_profile

The `watchdog_profile` setting is deprecated and will be removed in a future release. Instead, use the `failure_detection_sensitivity` policy for predefined thresholds and timeouts:

```sh
rladmin tune cluster failure_detection_sensitivity [ high | low ]
```

The `failure_detection_sensitivity` policy has the following options:

- `high` (previously known as `local-network watchdog_profile`) – high failure detection sensitivity, lower thresholds, and faster failure detection and failover

- `low` (previously known as `cloud watchdog_profile`) – low failure detection sensitivity and higher tolerance for latency variance (also called network jitter)

#### Ubuntu 16.04

Ubuntu 16 support is deprecated, and support will be removed in a future release.

#### Active-Active database persistence

The RDB snapshot option for [Active-Active database persistence](https://redis.io/docs/latest/operate/rs/databases/active-active/manage#data-persistence) is deprecated and will be removed in a future release.

Please plan to reconfigure any Active-Active databases to use append-only file (AOF) persistence with the following command:

```sh
crdb-cli crdb update --crdb-guid <CRDB_GUID> \
    --default-db-config '{"data_persistence": "aof", "aof_policy":"appendfsync-every-sec"}'
```

## Resolved issues

- RS97528 - Prevent [self-signed certificate](https://redis.io/docs/latest/operate/rs/security/certificates/create-certificates) script error on Ubuntu 20.04 by changing the user instructions.

- RS99643 - Fix [`cipher_suites`](https://redis.io/docs/latest/operate/rs/security/encryption/tls/ciphers) configuration to allow default cipher suites according to the control plane, data plane, and discovery service.

- RS99696 - Fix  [`HINCRBYFLOT`](https://github.com/redis/redis/security/advisories/GHSA-hjv8-vjf6-wcr6) CVE

- RS54226 - During upgrades, a CRDB worker process would intermittently get stuck in a restart loop. This issue is now fixed. 

## Known limitations

### Feature limitations

- RS78430 -  When [tuning module arguments](https://redis.io/docs/latest/operate/rs/references/cli-utilities/rladmin/tune#tune-db), any typo or use of unsupported arguments can cause shards to get stuck after restart.

### Operating system limitations

#### Ubuntu 20.04

By default, you cannot use the SHA1 hash algorithm ([OpenSSL’s default security level is set to 2](https://manpages.ubuntu.com/manpages/focal/man3/SSL_CTX_set_security_level.3ssl.html#notes)). The operating system will reject SHA1 certificates even if the `mtls_allow_weak_hashing` option is enabled. You need to replace SHA1 certificates with newer certificates that use SHA-256. Note that the certificates provided with Redis Enterprise Software use SHA-256.