The ping index is invalid: "ping" : ISODate("1970-01-01T00:00:00.001Z")
configsvr> db.lockpings.getIndexes()
[
{
"v" : 1,
"key" : {
"_id" : 1
},
"ns" : "config.lockpings",
"name" : "_id_"
},
{
"v" : 1,
"key" : {
"ping" : ISODate("1970-01-01T00:00:00.001Z")
},
"ns" : "config.lockpings",
"name" : "ping_"
}
]
configsvr>