Update LDR docs for GA & remove validated #19626
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| @@ -31,21 +29,16 @@ Conflicts at the KV level are detected when there is either: | |||
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| ### SQL level conflicts | |||
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| In `validated` mode, when a conflict cannot apply due to violating [constraints]({% link {{ page.version.version }}/constraints.md %}), for example, a foreign key constraint or schema constraint, it will be retried for up to a minute and then put in the [DLQ](#dead-letter-queue-dlq) if it could not be resolved. | |||
| When a conflict cannot apply due to violating [constraints]({% link {{ page.version.version }}/constraints.md %}), for example, a foreign key constraint or schema constraint, LDR will send the row to the [DLQ](#dead-letter-queue-dlq). | |||
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I believe in immeidate mode we don't even allow foreign key constraints
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I removed this reference.
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| For more details, refer to the LDR [Known limitations]({% link {{ page.version.version }}/logical-data-replication-overview.md %}#known-limitations). | ||
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| When you run LDR in [`immediate` mode](#modes), you cannot replicate a table with [foreign key constraints]({% link {{ page.version.version }}/foreign-key.md %}). In [`validated` mode](#modes), foreign key constraints **must** match. All constraints are enforced at the time of SQL/application write. | ||
| #### Unique secondary indexes |
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| ### Dead letter queue (DLQ) | ||
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| When the LDR job starts, it will create a DLQ table with each replicating table so that unresolved conflicts can be tracked. The DLQ will contain the writes that LDR cannot apply after the retry period, which could occur if: | ||
| When the LDR job starts, it will create a DLQ table with each replicating table so that unresolved conflicts can be tracked. The DLQ will contain the writes that LDR cannot apply after the retry period of a minute, which could occur if: |
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I think this list could be updated. I think it could read:
- Presence of Unique index on destination table (see section below)
- (only for 24.3) Loss of Quorum of the underlying ranges of the destination table
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we also prevent DROP table on LDR tables on all versions given cockroachdb/cockroach#136172
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Is this what you were thinking for the list (24.3) below @msbutler? lmk if I mixed things up at all...
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for 24.3:
- Presence of Unique index on destination table (see section below)
- Loss of Quorum of the underlying ranges of the destination table
for 25.1/2
- Presence of Unique index on destination table (see section below)
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ah, did not see the updated commit. you can remove "table schemas do not match"
| - The destination table was dropped. | ||
| - The destination cluster is unavailable. | ||
| - Tables schemas do not match. | ||
| - The destination table is unavailable. |
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we can remove the unavailable line and the table schemas line for 25.1 and 25.2
| @@ -39,7 +39,6 @@ When the LDR job starts, it will create a DLQ table with each replicating table | |||
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| - The destination table is unavailable. | |||
| - [Loss of quorum]({% link {{ page.version.version }}/architecture/replication-layer.md %}#overview) of the underlying [ranges]({% link {{ page.version.version }}/architecture/reads-and-writes-overview.md %}#range) in the destination table. | |||
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oof. sorry i should have caught this earlier. the first 2 bullets are essentially describing the same thing, so you could delete the first one.
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@alicia-l2 @jeffswenson can you check we landed where you wanted on the example? |
| When you run LDR in [`immediate` mode](#modes), you cannot replicate a table with [foreign key constraints]({% link {{ page.version.version }}/foreign-key.md %}). In [`validated` mode](#modes), foreign key constraints **must** match. All constraints are enforced at the time of SQL/application write. | ||
| #### Unique secondary indexes | ||
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| LDR cannot guarantee that the [_dead letter queue_ (DLQ)]({% link {{ page.version.version }}/manage-logical-data-replication.md %}) will remain empty if the destination table has a unique [secondary index]({% link {{ page.version.version }}/schema-design-indexes.md %}). The two clusters in LDR operate independently, so writes to one cluster can conflict with writes to the other. |
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i wonder if there is a way to rephrase the first sentence? we can't guarantee that the DLQ will remain empty even in situations where the destination table does not have a unique secondary index. maybe we can phrase it from more of a guidance perspective like 'to avoid DLQ entries we recommend no unique secondary indexes on the destination table?'
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I rephrased the first sentence here, ok?
Fixes DOC-13440
This PR:
validatedmode from all versions — for now, removed themodeoption andimmediatevalue because this is the default and only option.Preview
Navigate to pages from v25.2 Setup tutorial.