Avamar: SQL Transaction Log Backup Fails Parsing Sqlmeta.xml File Due to Log Gap Error

Avamar SQL log snips showing the issue loading sqlmeta.xml file:

2024/09/05-19:09:26.11299 [avsql_assist] avspawn::run_and_wait back from wait error_num:536870932 wait_error:0
2024/09/05-19:09:26.11299 [avsql_assist] called avspawnpipe::~avspawnpipe
2024/09/05-19:09:26.11299 [avsql_assist] avspawnpipe::~avspawnpipe done with avspawnpipe::wait stdout
2024/09/05-19:09:26.11400 [avsql_assist] called avspawnpipe::~avspawnpipe
2024/09/05-19:09:26.11400 [avsql_assist] avspawnpipe::~avspawnpipe done with avspawnpipe::wait stderr
2024-09-05 15:09:26 avsql Warning <7427>: Error loading SQL metadata
avtar Warning <18125>: Calling DDR_OPEN_VIA_TOKEN returned result code:5341 message:SSL library error
avtar Error <10542>: Data Domain server "chgava-dd01.na.int.grp" open failed DDR result code: 5341, desc: SSL library error
avtar Error <10512>: Problem logging into the DDR server index:1
2024/09/05-19:09:26.15899 [avsql_assist] <=== avsql_assist::sqlmeta_load_from_snapup
2024/09/05-19:09:26.16000 [avsql_assist] ===> sqlconnect::sqlconnect
2024/09/05-19:09:26.16000 [avsql_assist] ===> sqlconnect::connect
2024/09/05-19:09:26.16000 [avsql_assist] ===> sqlconnectimpl_smo::InitDll
2024/09/05-19:09:26.16000 [avsql_assist] SMO dll already loaded.
2024/09/05-19:09:26.16000 [avsql_assist] <=== sqlconnectimpl_smo::InitDll
2024/09/05-19:09:26.16100 [avsql_assist] ===> SMO_New()
2024/09/05-19:09:26.16100 [avsql_assist] <=== SMO_New()

The database entries in the sqlmeta.xml file are removed except for the system database. This occurs when Logical Sequence Number (LSN) validation during an incremental backup fails because all databases return a NULL LSN value except the system database.

[avsql_assist] Aligned before compare- Last backup (metadata) LSN: '0000000000000000000', Current (SQL Server) LSN: '1277000015962500001'

This resulted in a log‑gap error, while full SQL plug‑in backups for the same databases on the server continue to run without issues.

The SQL plug-in fails to load and parse sqlmeta.xml when handling many databases (≈255+). An internal buffer used by the avtar-spawn path is insufficient, returning incomplete metadata to the plug-in and triggering "Error loading SQL metadata" and downstream log‑gap detection. 

In certain Windows platforms, Avamar SQL incremental backup is failing with a 'log gap' error. Thus increasing the sqlmeta.xml file size from 32 MB to 128 MB addressed the problem. 

Fixes are available:

1. Avamar Version
   1. 19.4.100-116
      1. ESC 1026 
      2. Engineering binary
   2. 19.10.1-166
      1. Jira AVAMARESC-2610
      2. AVAMAR-47449
      3. Fix 338875 
   3. 19.12.100
      1. AVAMAR-47454
      2. Incorporated