tx index for height missing issue

[unclezoro]

A tool help to locate the issue: https://transfer.toolsfdg.net/get/cQVXe/index-viewer

follow the step:

1. Download the above binary.
2. Stop the node first.
3. ./index-viewer ${node-home} ${the height of missing index block} , for example:./index-viewer testnoded/ 21
4. It will print the tx hash at that height, for example:

➜  build git:(index-view) ✗ ./index-viewer testnoded/   21
8e97469e8ceb9dad764dd48695d321dcde72d5512b7b1b9030d3174d0196e1de

if the result is empty, the index data do not exist in db, need reproduce the issue.