Problem with historical tags and historical tables

Ignition
1

Hi!

We have a Ignition 8.1 redundancy system running and all the tags got 2 new entrance on sqlt_te and is causing problem on the chart or easychart

as is fetching info from the latest id, today at 11:30 was created the second id and later on after a restart at 13:49 was created the latest, so easy chart and chart is only showing data from 13:49. This happened to all the historical tags of the system. How can I fix this from the database ? what do I change without crashing the system so we can see the historical data.

Any thoughts?. I can change the id on the historical tables since 2022 to today to the latest id of every tag, but it will take an eternity

2

Hi Sebastian, before you make the following suggested changes make sure to perform a full database backup.

  • The issue you are seeing is because Ignition uses the created and retired timestamps in the sqlth_te (Tag Entries) table to determine which ID was active for a tag at any given time. When redundancy failovers or restarts create a new ID for an existing path, the previous ID is often marked as "retired." Because the chart queries for the currently active ID, it effectively ignores the older ID ranges.
  • Instead of updating every rows in the partition table e.g.sqlt_data_x_x table you can modify the sqlth_te table to make the latest ID appear as if it has been active since the beginning of your history.

  1. Identify the affected IDs: Find the old and new IDs for your tags in the sqlth_te table using their tagpath.

  2. Backdate the latest ID: Update the created column for the latest ID to a time before your earliest historical data (e.g., 2022-01-01).

3)Widen the Scan Class window: In the sqlth_sce (Scan Class Executions) table, update the start_time for the new entries to 0 (or a very old date). This ensures the historian doesn't mark old data as "stale" or outside the active driver's scope.

  1. Restart the History Provider: Go to the Gateway Webpage > Configure > Tags > History. Edit your history provider and click Save (you don't need to change any settings). This clears the internal cache and forces Ignition to read the updated metadata.

To prevent this from happening in the future you can do the following:

  • Use Active Time to Resolve Conflicts: Set this to True in your Redundancy settings (available in 8.1.31+) to help the backup push data to the master without creating duplicate tag records.

  • Backup History Level: Ensure this is set to Partial if you want the backup to cache data until the master's state is verified, reducing duplicate ID generation.