Pull replication(or sync) fails with remote sync gateway - couchbase

Question

I am currently working on a PoC to understand the CouchBase lite sync functionality(with Java application). The pull and push replication worked absolutely fine when the sync-gateway was running locally on my machine.
Now when I move my sync-gateway to a Remote machine, the pull replicator doesn't work. But the push works fine. From the following logs on the client seems like there has been some error with pull replicator.
JavaSQLiteStorageEngine
PULL replication event. Source: com.couchbase.lite.replicator.Replication#29fc9a67 Transition: INITIAL -> RUNNING Total changes: 0 Completed changes: 0
Mar 25, 2016 6:04:53 PM com.couchbase.lite.util.SystemLogger e
SEVERE: ChangeTracker: com.couchbase.lite.replicator.ChangeTracker#2ca40c2c: Change tracker got error 404
Mar 25, 2016 6:04:53 PM com.couchbase.lite.util.SystemLogger e
SEVERE: Sync: Change tracker stopped during continuous replication
PULL replication event. Source: com.couchbase.lite.replicator.Replication#29fc9a67 Transition: RUNNING -> IDLE Total changes: 0 Completed changes: 0
Mar 25, 2016 6:05:04 PM com.couchbase.lite.util.SystemLogger e
SEVERE: ChangeTracker: com.couchbase.lite.replicator.ChangeTracker#1b3ae860: Change tracker got error 404
Mar 25, 2016 6:05:04 PM com.couchbase.lite.util.SystemLogger e
SEVERE: Sync: Change tracker stopped during continuous replication
Following is my sync-gateway logs
2016-03-25T18:19:03.210Z HTTP: #267: GET /test/_local/fc25dac22b1cec1454f09c3ea41f763bc4a46b20 (as mehtab.syed)
2016-03-25T18:19:03.210Z HTTP: #267: --> 404 missing (0.2 ms)
2016-03-25T18:19:03.214Z HTTP: #268: GET /test/_local/31d8e5f89b0db31be77ea73f950068c2d5fe11f8 (as mehtab.syed)
2016-03-25T18:19:03.214Z HTTP: #268: --> 404 missing (0.2 ms)
2016-03-25T18:19:03.340Z HTTP: #269: GET /test/_changes%3ffeed=normal&heartbeat=300000&style=all_docs&active_only=true?feed=normal&heartbeat=300000&style=all_docs&active_only=true
2016-03-25T18:19:03.340Z HTTP: #269: --> 404 unknown URL (0.2 ms)
2016-03-25T18:19:13.475Z HTTP: #270: GET /test/_changes%3ffeed=normal&heartbeat=300000&style=all_docs&active_only=true?feed=normal&heartbeat=300000&style=all_docs&active_only=true
2016-03-25T18:19:13.475Z HTTP: #270: --> 404 unknown URL (0.2 ms)
2016-03-25T18:19:23.601Z HTTP: #271: GET /test/_changes%3ffeed=normal&heartbeat=300000&style=all_docs&active_only=true?feed=normal&heartbeat=300000&style=all_docs&active_only=true
2016-03-25T18:19:23.601Z HTTP: #271: --> 404 unknown URL (0.2 ms)
Further, I am using cookie authentication and following is my sync-gateway configuration.
{
"interface": "127.0.0.1:4988",
"adminInterface": "127.0.0.1:4989",
"log": [
"CRUD",
"REST+",
"Access"
],
"databases": {
"test": {
"server": "walrus:",
"users": {"GUEST": {"disabled": true,"admin_channels": ["*"]}
},
"sync": `function sync(doc,oldDoc){
if(doc.type=="user"){
channel("u-"+doc._id)
access(doc.owner,"u-"+doc._id)
}else if(doc.type=="expense"){
channel("e-"+doc.owner)
access(doc.owner,"e-"+doc.owner)
access(doc.approver,"e-"+doc.owner)
}else{
channel(doc.channels)
}
}`
}
}
}
Does anyone have any idea what might be wrong?