Hello Igniters.
We have very useful `index-reader` utility that can check index file
consistency.
I try to run it on several test and production Ignite deployments and found
that frequently util report orphaned pages inside index.bin file.
Example of output of production deployment:
```
Exception occurred on step 981750: Possibly orphan InlineInnerIO page,
pageId=844420636146422
Exception occurred on step 981759: Possibly orphan InlineInnerIO page,
pageId=844420636146431
Exception occurred on step 981775: Possibly orphan InlineInnerIO page,
pageId=844420636146447
Exception occurred on step 981790: Possibly orphan InlineInnerIO page,
pageId=844420636146462
Total pages encountered during sequential scan: 981844
Total errors occurred during sequential scan: 44853
```
Test deployment:
```
Error [step=10876, msg=Possibly orphan InlineInnerIO page,
pageId=844420635175548]
Error [step=11048, msg=Possibly orphan InlineInnerIO page,
pageId=844420635175720]
Error [step=11081, msg=Possibly orphan InlineInnerIO page,
pageId=844420635175753]
Error [step=11119, msg=Possibly orphan InlineInnerIO page,
pageId=844420635175791]
Error [step=11169, msg=Possibly orphan InlineInnerIO page,
pageId=844420635175841]
----
Total pages encountered during sequential scan: 11543
Total errors occurred during sequential scan: 88
```
So my questions are
- Do we know the way how orphaned pages sneaks into index.bin?
- Do we have tickets/fixes to prevent this situation?
- How Ignite admin should fix this in real-world deployments?
