Hi. We have 7 servers in prod in two networks (uk and nl) where one of these servers is Arbiter and another one is Hidden. We encountered a problem with elections despite the fact all servers were online (without network issues): all servers were in the state SECONDARY and we didn't see any error in logs.

I attached a configurations. I suppose we had a majority in such situation

What can be a problem? 

 

[

{ "_id" : 3, "name" : "uk1:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 74206, "optime" : Timestamp(1552820007, 13), "optimeDate" : ISODate("2019-03-17T10:53:27Z"), "lastHeartbeat" : ISODate("2019-03-17T10:53:27.621Z"), "lastHeartbeatRecv" : ISODate("2019-03-17T10:53:27.664Z"), "pingMs" : NumberLong(13), "electionTime" : Timestamp(1552738992, 1), "electionDate" : ISODate("2019-03-16T12:23:12Z"), "configVersion" : 498059 }

,

{ "_id" : 4, "name" : "uk2:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 74206, "optime" : Timestamp(1552820007, 13), "optimeDate" : ISODate("2019-03-17T10:53:27Z"), "lastHeartbeat" : ISODate("2019-03-17T10:53:27.621Z"), "lastHeartbeatRecv" : ISODate("2019-03-17T10:53:27.278Z"), "pingMs" : NumberLong(13), "syncingTo" : "uk1:27017", "configVersion" : 498059 }

,

{ "_id" : 5, "name" : "nl1:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 74206, "optime" : Timestamp(1552820007, 13), "optimeDate" : ISODate("2019-03-17T10:53:27Z"), "lastHeartbeat" : ISODate("2019-03-17T10:53:27.596Z"), "lastHeartbeatRecv" : ISODate("2019-03-17T10:53:27.398Z"), "pingMs" : NumberLong(7), "syncingTo" : "uk1:27017", "configVersion" : 498059 }

,

{ "_id" : 6, "name" : "nl2:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 74206, "optime" : Timestamp(1552820007, 13), "optimeDate" : ISODate("2019-03-17T10:53:27Z"), "lastHeartbeat" : ISODate("2019-03-17T10:53:27.596Z"), "lastHeartbeatRecv" : ISODate("2019-03-17T10:53:25.885Z"), "pingMs" : NumberLong(7), "syncingTo" : "uk1:27017", "configVersion" : 498059 }

,

{ "_id" : 7, "name" : "az1:27017", "health" : 1, "state" : 7, "stateStr" : "ARBITER", "uptime" : 10951400, "syncingTo" : "nl1:27017", "infoMessage" : "syncing from: nl1wv8912:27017", "configVersion" : 498059, "self" : true }

,

{ "_id" : 8, "name" : "uk2:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 74206, "optime" : Timestamp(1552820007, 13), "optimeDate" : ISODate("2019-03-17T10:53:27Z"), "lastHeartbeat" : ISODate("2019-03-17T10:53:27.622Z"), "lastHeartbeatRecv" : ISODate("2019-03-17T10:53:27.623Z"), "pingMs" : NumberLong(14), "syncingTo" : "uk2:27017", "configVersion" : 498059 }

,

{ "_id" : 9, "name" : "nl3:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 74206, "optime" : Timestamp(1552820007, 13), "optimeDate" : ISODate("2019-03-17T10:53:27Z"), "lastHeartbeat" : ISODate("2019-03-17T10:53:27.596Z"), "lastHeartbeatRecv" : ISODate("2019-03-17T10:53:26.222Z"), "pingMs" : NumberLong(7), "syncingTo" : "nl2:27017", "configVersion" : 498059 }

]

{
"_id" : 3,
"host" : "uk1:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 10,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 4,
"host" : "uk2:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 3,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 5,
"host" : "nl1:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 6,
"host" : "nl2:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 7,
"host" : "az1:27017",
"arbiterOnly" : true,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 8,
"host" : "uk3:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : true,
"priority" : 0,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 9,
"host" : "nl3:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {

},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],