livesync-pg: Refactor steps and add instructions to view replication lag #4235
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Signed-off-by: Arunprasad Rajkumar <[email protected]>
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Allow 10 minutes from last push for the staging site to build. If the link doesn't work, try using incognito mode instead. For internal reviewers, check web-documentation repo actions for staging build status. Link to build for this PR: http://docs-dev.timescale.com/docs-arajkumar-refator-lm-instr |
arajkumar
changed the title
billy-the-fish
requested changes
Jun 26, 2025
| @@ -127,6 +127,48 @@ EOF | |||
| </Procedure> | |||
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| ## Specify the tables to synchronize | |||
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| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the SOURCE database to | |||
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| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the SOURCE database to | |
| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the source database that |
| ## Specify the tables to synchronize | ||
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| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the SOURCE database to | ||
| specify the list of tables which you intend to synchronize. |
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Suggested change
| specify the list of tables which you intend to synchronize. | |
| specifies the tables to synchronize. |
| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the SOURCE database to | ||
| specify the list of tables which you intend to synchronize. | ||
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| For example: |
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| <Procedure> | ||
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| 1. **Create a publication named `analytics` which publishes `metrics` and `tags` tables** |
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| 1. **Create a publication named `analytics` which publishes `metrics` and `tags` tables** | |
| 1. **Create a publication that specifies the table to synchronize** |
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| 1. **Create a publication named `analytics` which publishes `metrics` and `tags` tables** | ||
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| `PUBLICATION` enables you to add all the tables in the schema or even all the tables in the database. However, it |
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| `PUBLICATION` enables you to add all the tables in the schema or even all the tables in the database. However, it | |
| A `PUBLICATION` enables you to synchronize some or all the tables in the schema or database. |
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| For example, to synchronize both `analytics` and `iot` publications: | ||
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| ```shell | ||
| docker run -d --rm --name livesync timescale/live-sync:v0.1.16 run --publication analytics --publication iot --subscription livesync --source $SOURCE --target $TARGET |
| 1. **View the tables being synchronized** | ||
| 1. **View the progress of tables being synchronized** | ||
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| List the tables being synchronized by $LIVESYNC using the `_ts_live_sync.subscription_rel` table in the target $SERVICE_LONG: | ||
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| ```bash | ||
| psql $TARGET -c "SELECT * FROM _ts_live_sync.subscription_rel" | ||
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```
You see something like the following:
If you could turn the table into a markdown table, that would be great.
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| `rows_copied` indicates rows copied so far during the initial sync. | ||
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| `approximate_rows` indicates the approximate number of rows in the table. | ||
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| `bytes_copied` indicates the number of bytes copied so far during the initial sync. | ||
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| `approximate_size` indicates the approximate size of the table in bytes. |
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I would not bother with these as the table titles are clear enough. Possibly a one liner saying all values are from the start of the sync.
| `approximate_size` indicates the approximate size of the table in bytes. | ||
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| To see the replication lag, run the following against the SOURCE database: |
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Can you check your indenting please.
| psql $SOURCE -c "SELECT slot_name, pg_size_pretty(pg_current_wal_flush_lsn() - confirmed_flush_lsn) AS lag FROM pg_replication_slots WHERE slot_name LIKE 'live_sync_%' AND slot_type = 'logical'" | ||
| ``` | ||
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| 1. **Add or remove tables from the publication** |
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I like this, can you do the same for the add and drop tables from the publication earlier to be consistent please.
JamesGuthrie
approved these changes
Jun 26, 2025
| @@ -127,6 +127,48 @@ EOF | |||
| </Procedure> | |||
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| ## Specify the tables to synchronize | |||
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| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the SOURCE database to | |||
There was a problem hiding this comment.
Suggested change
| After the schema is migrated, you [`CREATE PUBLICATION`][create-publication] on the SOURCE database to | |
| After the schema is migrated, you use [`CREATE PUBLICATION`][create-publication] on the SOURCE database to |
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| 1. **Create a publication named `analytics` which publishes `metrics` and `tags` tables** | ||
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| `PUBLICATION` enables you to add all the tables in the schema or even all the tables in the database. However, it |
There was a problem hiding this comment.
Suggested change
| `PUBLICATION` enables you to add all the tables in the schema or even all the tables in the database. However, it | |
| You can use `CREATE PUBLICATION` to add all the tables in a schema or all the tables in the database. However, it |
| CREATE PUBLICATION analytics FOR TABLE metrics, tags; | ||
| ``` | ||
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| 1. **Add tables after to an existing publication with a call to [ALTER PUBLICATION][alter-publication]** |
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Suggested change
| 1. **Add tables after to an existing publication with a call to [ALTER PUBLICATION][alter-publication]** | |
| 1. **Add tables to an existing publication with a call to [ALTER PUBLICATION][alter-publication]** |
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