> Hi John,

> Thanks for the additional information.

> It seems that you have corruption in your 'player' collection, but it may
> be hard to diagnose what is wrong or how it got that way.  Can you check
> the Windows Event Log and see if there are any NTFS-related errors reported?

> The "keysPerIndex" count for _id should match the document count, but it
> is lower by 24 documents.  The padding factor of about 1.66 suggests that
> there has been a lot of document movement over time, which can cause the
> indexes to be updated a lot, so a hard crash without journaling enabled
> might have left the index incompletely updated.  A hard crash with
> journaling should not be able to do this, unless the disk itself has
> problems or you ran out of disk space at a crucial moment.

> Because the validate command did not report any index problems, it looks
> like the _id index is just incomplete, but all keys are in-order and
> findable.

> Because your attempt to index the collection went into an infinite loop,
> I'm afraid that validate({full:true}) would do the same thing, but you
> could try it and see, assuming that there is a time when blocking updates
> for an extended period would not be a problem.  Validate with the full
> option should tell us more about what is wrong.

> If you want, you could create a Community Private ticket and upload a copy
> of your database for us to look at, but it's hard to know in advance
> whether we would be able to determine anything other than some details of
> what the corruption is; we might be able to figure out what happened, but
> we might not.  Even if uploading your database is not an attractive option,
> it would be valuable to create a "Core server" Jira ticket to collect as
> many details as possible so that we can correlate this information with
> other reports that we may get.

> The safest way to repair the database, assuming that you have available
> disk space, is to use mongodump with the --repair option to extract
> everything possible from the database and then use mongorestore to restore
> it to a fresh database, leaving the original to the side until you have
> verified that your new copy works properly and is not missing anything.
>  mongodump is documented at
> http://docs.mongodb.org/manual/reference/mongodump/ .

> Let us know how you'd like to proceed.

> Tad

> On Sunday, September 30, 2012 3:14:17 AM UTC-4, John Murdoch wrote:

>> Hi, Tad, I tried to respond earlier but somehow the message got stuck in
>> moderation.

>> On Thursday, September 20, 2012 12:40:23 AM UTC+1, Tad Marshall wrote:

>>> Is this a capped collection?  The case I've seen of an infinite index
>>> build was in a capped collection that had looped back into itself.  Other
>>> commands besides index builds will also loop forever;
>>> db.collection.find().itcount() for example.

>>>  No, it is not.

>>> Has this server had a hard crash such that it had to recover using the
>>> journal?  

>> Yes, it has seen crashes, it is a development server whose process I've
>> had to sometimes kill.

>> > Is this part of a replica set?  Primary or secondary (or both at
>> different times)?

>> No it is not.

>>> Can you run db.<collection>.validate() and post the output?  This will
>>> not loop forever (so long as you don't use the {full:true} variant).

>> > db.player.validate()
>> {
>>         "ns" : "wot.player",
>>         "firstExtent" : "1:1f8c000 ns:wot.player",
>>         "lastExtent" : "2c:2000 ns:wot.player",
>>         "extentCount" : 41,
>>         "datasize" : 23240866636,
>>         "nrecords" : 5576219,
>>         "lastExtentSize" : 2146426864,
>>         "padding" : 1.659999999958666,
>>         "firstExtentDetails" : {
>>                 "loc" : "1:1f8c000",
>>                 "xnext" : "1:1fa0000",
>>                 "xprev" : "null",
>>                 "nsdiag" : "wot.player",
>>                 "size" : 81920,
>>                 "firstRecord" : "1:1f8fa58",
>>                 "lastRecord" : "1:1f93474"
>>         },
>>         "deletedCount" : 731321,
>>         "deletedSize" : 1960113780,
>>         "nIndexes" : 1,
>>         "keysPerIndex" : {
>>                 "wot.player.$_id_" : 5576195
>>         },
>>         "valid" : true,
>>         "errors" : [ ],
>>         "warning" : "Some checks omitted for speed. use {full:true}
>> option to do
>>  more thorough scan.",
>>         "ok" : 1
>> }