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  1. Core Server
  2. SERVER-13583

mongostat shows queued inserts as readers

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Won't Fix
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: Diagnostics, Tools
    • Labels:
    • Backwards Compatibility:
      Major Change
    • Operating System:
      ALL

      Description

      While running an insert-only test, I noticed that mongostat shows queued readers, while I do not read anything.

      Sample mongostat output:

      insert  query update delete getmore command flushes mapped  vsize    res faults   locked db idx miss %     qr|qw   ar|aw  netIn netOut  conn       time
        6120     *0     *0     *0       0     2|0       0    16g  32.3g  1.97g      0  test:68.3%          0      19|0     0|1     6m     3k    23   19:33:03
        6061     *0     *0     *0       0     2|0       0    18g  36.3g  1.99g      1  test:76.4%          0      19|0     0|1     6m     8k    23   19:33:04
        5966     *0     *0     *0       0     1|0       0    18g  36.3g  2.02g      0  test:63.3%          0      19|0     0|1     6m     3k    23   19:33:05
        6110     *0     *0     *0       0     1|0       0    18g  36.3g  2.04g      0  test:68.4%          0      19|0     0|1     6m     3k    23   19:33:06

      db.currentOp output for the same time:

      > db.currentOp()
      {
      	"inprog" : [
      		{
      			"opid" : 824735,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60486",
      			"desc" : "conn62",
      			"threadId" : "0x7f37873b4700",
      			"connectionId" : 62,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824726,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60494",
      			"desc" : "conn72",
      			"threadId" : "0x7f37871b2700",
      			"connectionId" : 72,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824740,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60484",
      			"desc" : "conn63",
      			"threadId" : "0x7f3f851a3700",
      			"connectionId" : 63,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824743,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60493",
      			"desc" : "conn71",
      			"threadId" : "0x7f3f855a7700",
      			"connectionId" : 71,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824739,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60489",
      			"desc" : "conn67",
      			"threadId" : "0x7f3f850a2700",
      			"connectionId" : 67,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824741,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60499",
      			"desc" : "conn77",
      			"threadId" : "0x7f3f859ab700",
      			"connectionId" : 77,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824733,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60497",
      			"desc" : "conn75",
      			"threadId" : "0x7f3f854a6700",
      			"connectionId" : 75,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824725,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60495",
      			"desc" : "conn73",
      			"threadId" : "0x7f3786dae700",
      			"connectionId" : 73,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824727,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60501",
      			"desc" : "conn79",
      			"threadId" : "0x7f3f853a5700",
      			"connectionId" : 79,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824728,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60483",
      			"desc" : "conn65",
      			"threadId" : "0x7f3786eaf700",
      			"connectionId" : 65,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824736,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60496",
      			"desc" : "conn74",
      			"threadId" : "0x7f3786fb0700",
      			"connectionId" : 74,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824738,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60490",
      			"desc" : "conn68",
      			"threadId" : "0x7f37870b1700",
      			"connectionId" : 68,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824742,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60488",
      			"desc" : "conn66",
      			"threadId" : "0x7f37872b3700",
      			"connectionId" : 66,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824732,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60498",
      			"desc" : "conn76",
      			"threadId" : "0x7f3f85cae700",
      			"connectionId" : 76,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824730,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60491",
      			"desc" : "conn69",
      			"threadId" : "0x7f3f85aac700",
      			"connectionId" : 69,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824729,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60487",
      			"desc" : "conn64",
      			"threadId" : "0x7f3f85daf700",
      			"connectionId" : 64,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824734,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60500",
      			"desc" : "conn78",
      			"threadId" : "0x7f3f856a8700",
      			"connectionId" : 78,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824731,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60502",
      			"desc" : "conn80",
      			"threadId" : "0x7f3f852a4700",
      			"connectionId" : 80,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		},
      		{
      			"opid" : 824737,
      			"active" : false,
      			"op" : "insert",
      			"ns" : "",
      			"insert" : {
       
      			},
      			"client" : "10.61.157.244:60503",
      			"desc" : "conn81",
      			"threadId" : "0x7f3f857a9700",
      			"connectionId" : 81,
      			"locks" : {
      				"^test" : "W"
      			},
      			"waitingForLock" : true,
      			"numYields" : 0,
      			"lockStats" : {
      				"timeLockedMicros" : {
       
      				},
      				"timeAcquiringMicros" : {
       
      				}
      			}
      		}
      	]
      }

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              Assignee:
              Unassigned
              Reporter:
              alex.komyagin Alexander Komyagin
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                Created:
                Updated:
                Resolved: