[SPARK-19824][CORE] Update JsonProtocol to keep consistent with the UI
## What changes were proposed in this pull request?
Fix any inconsistent part in JsonProtocol with the UI.
This PR also contains the modifications in #17181
## How was this patch tested?
Updated JsonProtocolSuite.
Before this change, localhost:8080/json shows:
```
{
"url" : "spark://xingbos-MBP.local:7077",
"workers" : [ {
"id" : "worker-20170615172946-192.168.0.101-49450",
"host" : "192.168.0.101",
"port" : 49450,
"webuiaddress" : "http://192.168.0.101:8081",
"cores" : 8,
"coresused" : 8,
"coresfree" : 0,
"memory" : 15360,
"memoryused" : 1024,
"memoryfree" : 14336,
"state" : "ALIVE",
"lastheartbeat" : 1497519481722
}, {
"id" : "worker-20170615172948-192.168.0.101-49452",
"host" : "192.168.0.101",
"port" : 49452,
"webuiaddress" : "http://192.168.0.101:8082",
"cores" : 8,
"coresused" : 8,
"coresfree" : 0,
"memory" : 15360,
"memoryused" : 1024,
"memoryfree" : 14336,
"state" : "ALIVE",
"lastheartbeat" : 1497519484160
}, {
"id" : "worker-20170615172951-192.168.0.101-49469",
"host" : "192.168.0.101",
"port" : 49469,
"webuiaddress" : "http://192.168.0.101:8083",
"cores" : 8,
"coresused" : 8,
"coresfree" : 0,
"memory" : 15360,
"memoryused" : 1024,
"memoryfree" : 14336,
"state" : "ALIVE",
"lastheartbeat" : 1497519486905
} ],
"cores" : 24,
"coresused" : 24,
"memory" : 46080,
"memoryused" : 3072,
"activeapps" : [ {
"starttime" : 1497519426990,
"id" : "app-20170615173706-0001",
"name" : "Spark shell",
"user" : "xingbojiang",
"memoryperslave" : 1024,
"submitdate" : "Thu Jun 15 17:37:06 CST 2017",
"state" : "RUNNING",
"duration" : 65362
} ],
"completedapps" : [ {
"starttime" : 1497519250893,
"id" : "app-20170615173410-0000",
"name" : "Spark shell",
"user" : "xingbojiang",
"memoryperslave" : 1024,
"submitdate" : "Thu Jun 15 17:34:10 CST 2017",
"state" : "FINISHED",
"duration" : 116895
} ],
"activedrivers" : [ ],
"status" : "ALIVE"
}
```
After the change:
```
{
"url" : "spark://xingbos-MBP.local:7077",
"workers" : [ {
"id" : "worker-20170615175032-192.168.0.101-49951",
"host" : "192.168.0.101",
"port" : 49951,
"webuiaddress" : "http://192.168.0.101:8081",
"cores" : 8,
"coresused" : 8,
"coresfree" : 0,
"memory" : 15360,
"memoryused" : 1024,
"memoryfree" : 14336,
"state" : "ALIVE",
"lastheartbeat" : 1497520292900
}, {
"id" : "worker-20170615175034-192.168.0.101-49953",
"host" : "192.168.0.101",
"port" : 49953,
"webuiaddress" : "http://192.168.0.101:8082",
"cores" : 8,
"coresused" : 8,
"coresfree" : 0,
"memory" : 15360,
"memoryused" : 1024,
"memoryfree" : 14336,
"state" : "ALIVE",
"lastheartbeat" : 1497520280301
}, {
"id" : "worker-20170615175037-192.168.0.101-49955",
"host" : "192.168.0.101",
"port" : 49955,
"webuiaddress" : "http://192.168.0.101:8083",
"cores" : 8,
"coresused" : 8,
"coresfree" : 0,
"memory" : 15360,
"memoryused" : 1024,
"memoryfree" : 14336,
"state" : "ALIVE",
"lastheartbeat" : 1497520282884
} ],
"aliveworkers" : 3,
"cores" : 24,
"coresused" : 24,
"memory" : 46080,
"memoryused" : 3072,
"activeapps" : [ {
"id" : "app-20170615175122-0001",
"starttime" : 1497520282115,
"name" : "Spark shell",
"cores" : 24,
"user" : "xingbojiang",
"memoryperslave" : 1024,
"submitdate" : "Thu Jun 15 17:51:22 CST 2017",
"state" : "RUNNING",
"duration" : 10805
} ],
"completedapps" : [ {
"id" : "app-20170615175058-0000",
"starttime" : 1497520258766,
"name" : "Spark shell",
"cores" : 24,
"user" : "xingbojiang",
"memoryperslave" : 1024,
"submitdate" : "Thu Jun 15 17:50:58 CST 2017",
"state" : "FINISHED",
"duration" : 9876
} ],
"activedrivers" : [ ],
"completeddrivers" : [ ],
"status" : "ALIVE"
}
```
Author: Xingbo Jiang <xingbo.jiang@databricks.com>
Closes #18303 from jiangxb1987/json-protocol.
ea542d29b2