SAP Alert
Mark Mergaerts

Expertum Tech Alert 2

 21-Dec-2017 10:33:04 by Mark Mergaerts

 

HANA on IBM Power: Potential Row Store Corruption

 

          This Alert only applies to SAP HANA systems running on the IBM Power platform.

   Other platforms are NOT affected.

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SAP Note

2577314 - Possible Row Store Inconsistency on IBM Power Platform

Problem description

You may encounter inconsistencies in row store tables and/or during table consistency checks. Any of the following errors might be reported:

    5984;variable part double reference

    5986;pointing to free variable part found

    5989;savepoint version mismatch between page and persistence

Errors may also occur during startup:

table content corruption identified during RS index build: schema = "<schema>", table = "<table>", index = "<index>"

external reference in v-slot corrupted: record_ID = 0000000

invalid v-slot pointer (wrong page header) identified during variable-size field traversal: storage_type = VGROUP, v-slot = 000000

slot sanity check failure

Affected HANA releases

Following releases are vulnerable to the problem:

1.0 SPS 08-SPS 11 All revisions
1.0 SPS 12

Revisions <= 122.14

2.0 SPS 00 All revisions
2.0 SPS 01 Revisions <= 012.03
2.0 SPS 02 Revisions <= 022

Cause and solution

The problem is caused by an error in the savepoint logic for IBM Power, which causes a discrepancy between the row store page in memory and the image of the page in persistent storage.

SAP is currently working on a permanent solution, but no such solution is available yet. Please follow the updates to note 2577314.

Workaround

  • If a table consistency check reports error 5989 and the indexserver has not been restarted, then it is possible, using a manual procedure, to flush the page in memory (which at this point is still consistent) to persistent storage. The procedure is explained in detail in the note. Do not restart the HANA system before carrying out this fix.
  • If the consistency check reports error 5989 and the indexserver has been restarted, then a point-in-time recovery is needed; see "Case 2" in the note
  • In case of errors 5984 or 5986, the inconsistency is permanent and you should contact HANA development via an incident in the SAP Support Portal (component HAN-DB)

 Key SAP Notes

Note

Subject

2577314

Possible Row Store Inconsistency on IBM Power Platform

1977584

Technical Consistency Checks for SAP HANA Databases

2116157

FAQ: SAP HANA Consistency Checks and Corruptions

 

Topics: HANA, IBM