m31001| 2015-01-02T13:58:36.389-0500 E STORAGE  [rsSync] WiredTiger (22) [1420225116:389045][2313:0x4ae7f940], file:collection-6-6815905439142955799.wt, cursor.search_near: requires key be set: Invalid argument
 m31001| 2015-01-02T13:58:36.389-0500 I -        [rsSync] Invariant failure: ret resulted in status BadValue 22: Invalid argument at src/mongo/db/storage/wiredtiger/wiredtiger_record_store.cpp 424
 m31001| 2015-01-02T13:58:36.394-0500 I CONTROL  [rsSync] 
 m31001|  0xf17859 0xec1671 0xea8a5a 0xd3aa63 0xd3be5e 0x8ef1fe 0x8f085d 0xc157c7 0xc71572 0xc71a96 0xc72531 0xc69b0f 0xf63b64 0x7f8ffd8ab73d 0x7f8ffca83d1d
 m31001| ----- BEGIN BACKTRACE -----
 m31001| {"backtrace":[{"b":"400000","o":"B17859"},{"b":"400000","o":"AC1671"},{"b":"400000","o":"AA8A5A"},{"b":"400000","o":"93AA63"},{"b":"400000","o":"93BE5E"},{"b":"400000","o":"4EF1FE"},{"b":"400000","o":"4F085D"},{"b":"400000","o":"8157C7"},{"b":"400000","o":"871572"},{"b":"400000","o":"871A96"},{"b":"400000","o":"872531"},{"b":"400000","o":"869B0F"},{"b":"400000","o":"B63B64"},{"b":"7F8FFD8A5000","o":"673D"},{"b":"7F8FFC9B0000","o":"D3D1D"}],"processInfo":{ "mongodbVersion" : "2.8.0-rc5-pre-", "gitVersion" : "0d93899c9031cfb776bad7e1b0f6ab9703fb2aea", "uname" : { "sysname" : "Linux", "release" : "2.6.32-431.3.1.el6.x86_64", "version" : "#1 SMP Fri Jan 3 21:39:27 UTC 2014", "machine" : "x86_64" }, "somap" : [ { "elfType" : 2, "b" : "400000" }, { "b" : "7FFF32627000", "elfType" : 3 }, { "b" : "7F8FFD8A5000", "path" : "/lib64/libpthread.so.0", "elfType" : 3 }, { "b" : "7F8FFD69C000", "path" : "/lib64/librt.so.1", "elfType" : 3 }, { "b" : "7F8FFD498000", "path" : "/lib64/libdl.so.2", "elfType" : 3 }, { "b" : "7F8FFD198000", "path" : "/usr/lib64/libstdc++.so.6", "elfType" : 3 }, { "b" : "7F8FFCF15000", "path" : "/lib64/libm.so.6", "elfType" : 3 }, { "b" : "7F8FFCD07000", "path" : "/lib64/libgcc_s.so.1", "elfType" : 3 }, { "b" : "7F8FFC9B0000", "path" : "/lib64/libc.so.6", "elfType" : 3 }, { "b" : "7F8FFDAC0000", "path" : "/lib64/ld-linux-x86-64.so.2", "elfType" : 3 } ] }}
 m31001|  mongod(_ZN5mongo15printStackTraceERSo+0x29) [0xf17859]
 m31001|  mongod(_ZN5mongo10logContextEPKc+0xE1) [0xec1671]
 m31001|  mongod(_ZN5mongo17invariantOKFailedEPKcRKNS_6StatusES1_j+0xDA) [0xea8a5a]
 m31001|  mongod(_ZN5mongo21WiredTigerRecordStore20cappedDeleteAsNeededEPNS_16OperationContextERKNS_8RecordIdE+0x673) [0xd3aa63]
 m31001|  mongod(_ZN5mongo21WiredTigerRecordStore12insertRecordEPNS_16OperationContextEPKcib+0x1CE) [0xd3be5e]
 m31001|  mongod(_ZN5mongo10Collection15_insertDocumentEPNS_16OperationContextERKNS_7BSONObjEb+0x4E) [0x8ef1fe]
 m31001|  mongod(_ZN5mongo10Collection14insertDocumentEPNS_16OperationContextERKNS_7BSONObjEb+0x8D) [0x8f085d]
 m31001|  mongod(_ZN5mongo4repl11_logOpObjRSEPNS_16OperationContextERKNS_7BSONObjE+0x1C7) [0xc157c7]
 m31001|  mongod(_ZN5mongo4repl8SyncTail15applyOpsToOplogEPNS_16OperationContextEPSt5dequeINS_7BSONObjESaIS5_EE+0xE2) [0xc71572]
 m31001|  mongod(_ZN5mongo4repl8SyncTail10multiApplyEPNS_16OperationContextERSt5dequeINS_7BSONObjESaIS5_EE+0x3F6) [0xc71a96]
 m31001|  mongod(_ZN5mongo4repl8SyncTail16oplogApplicationEv+0x131) [0xc72531]
 m31001|  mongod(_ZN5mongo4repl13runSyncThreadEv+0x1EF) [0xc69b0f]
 m31001|  mongod(+0xB63B64) [0xf63b64]
 m31001|  libpthread.so.0(+0x673D) [0x7f8ffd8ab73d]
 m31001|  libc.so.6(clone+0x6D) [0x7f8ffca83d1d]
 m31001| -----  END BACKTRACE  -----
 m31001| 2015-01-02T13:58:36.394-0500 I -        [rsSync] 
 m31001| 
 m31001| ***aborting after invariant() failure