Redis 8.6 introduces improvements to stream reliability, memory management, and security. It also has two known limitations that can affect Redis Search cursor results and idempotent stream writes:
Redis Search cursors may miss results during load rebalancing operations.
XADD with IDMP or IDMPAUTO should not be used with a specific non-default AOF configuration.
Use the Quick Fix table to identify the applicable limitation, review Prerequisites, follow the guidance under Redis Search cursors or Stream idempotency, and use Troubleshooting to collect the information Redis Support needs.
Quick Fix
| What you see | What to do |
|---|---|
| A cursor-based search returns fewer results than expected during or near a database rebalancing operation | Wait for the operation to finish, then rerun the search and compare the results. |
| Results change between cursor requests | Record the query, cursor sequence, result counts, and timestamps. Determine whether database rebalancing was occurring. |
| Results remain incomplete after rebalancing finishes | Contact Redis Support with the database ID, sanitized query, cursor sequence, expected and observed result counts, and timestamps. |
An application uses XADD with IDMP or IDMPAUTO
|
Record the database’s data-persistence selection and contact Redis Support to confirm whether the affected AOF configuration applies. |
| You are unsure whether the database is affected | Confirm that the database runs Redis 8.6 and collect the database ID, region, affected command or query, and timestamps. |
Prerequisites
Before troubleshooting:
Confirm the database version. Verify that the affected database runs Redis 8.6.
Record the database details. Collect the subscription ID, database ID, deployment region, and approximate time of the behavior.
Review recent activity. Check for visible database events or configuration changes around the time the issue occurred.
Sanitize diagnostic information. Remove passwords, tokens, customer data, and other sensitive information from queries, commands, logs, and reproductions.
Review the documented limitations. See the Redis 8.6 release notes and breaking changes.
Redis Search cursors during load rebalancing
What is the limitation?
During load rebalancing operations, including atomic slot migration, data can move between nodes. While that movement is occurring, a Redis Search cursor may miss some results.
This behavior does not necessarily mean that matching documents were deleted or that the search index is permanently inconsistent.
Common symptoms
You may see:
A cursor-based search returning fewer results than expected.
Results changing between cursor requests.
A query returning the expected results after the rebalancing operation finishes.
What to do
Confirm that the database runs Redis 8.6.
Record when the incomplete results occurred, including the timestamp and timezone.
Check for visible database operations or events occurring at that time.
If load rebalancing or slot migration is not visible in the Redis Cloud Console, contact Redis Support to confirm whether data movement was occurring.
After the operation finishes, rerun the search and compare the results.
-
If results remain incomplete, contact Redis Support with:
The database ID and deployment region.
The sanitized query.
The cursor sequence.
The expected and observed result counts.
Timestamps with timezone.
A minimal reproduction, when available.
Stream idempotency and AOF configuration
What is the limitation?
Avoid XADD with IDMP or IDMPAUTO when both of the following configuration settings apply:
appendonly yes
aof-use-rdb-preamble no
The aof-use-rdb-preamble no setting is non-default. Redis Cloud manages internal database configuration, and customers may not be able to inspect or change these settings directly.
What to do
Confirm that the database runs Redis 8.6.
Confirm whether the application uses XADD with IDMP or IDMPAUTO.
Record the database’s Data persistence selection from the Redis Cloud Console.
Do not use CONFIG SET or attempt to change managed Redis configuration settings as a workaround.
Contact Redis Support to confirm whether the affected AOF configuration applies to the database.
Until the configuration is confirmed, avoid adopting IDMP or IDMPAUTO for the affected workload.
-
If unexpected stream behavior has already occurred, provide Redis Support with:
The database ID and deployment region.
The sanitized XADD command pattern.
Whether IDMP or IDMPAUTO is used.
The Data persistence selection.
Timestamps with timezone.
The expected and observed stream behavior.
A minimal reproduction, when available.
Troubleshooting
| Issue | What to check |
|---|---|
| Search results are incomplete during a cursor sequence | Confirm the Redis version and record whether database rebalancing or another operation was occurring. |
| Search results remain incomplete after the operation finishes | Rerun the query, capture the complete cursor sequence, and contact Redis Support. |
| You cannot determine whether rebalancing occurred | Provide the database ID and timestamps so Redis Support can investigate the database activity. |
You cannot inspect appendonly or aof-use-rdb-preamble
|
Record the Data persistence selection shown in the Redis Cloud Console. Redis Support can confirm whether the affected internal configuration applies. |
Stream behavior is unexpected with IDMP or IDMPAUTO
|
Stop using the affected option for new writes where operationally safe, preserve diagnostic information, and contact Redis Support. |
| The behavior occurs on a version other than Redis 8.6 | Contact Redis Support with the actual database version and reproduction details. Do not assume the Redis 8.6 limitation is the cause. |
Need more help?
Contact Redis Support when:
Search results remain incomplete after rebalancing has finished.
You cannot determine whether data movement was occurring.
An application uses IDMP or IDMPAUTO and you need confirmation that the database uses the affected AOF configuration.
Stream behavior is unexpected while using the affected command and configuration combination.
Include the subscription ID, database ID, deployment region, Redis version, timestamps with timezone, sanitized commands or queries, expected and observed behavior, and a minimal reproduction when available.
Do not include passwords, tokens, customer data, or other secrets in a Support request.
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