Transactions timed out in YCSB with latest 3.X SDK

Transactions are timing out in YCSB on recent mad-hatter build 6.5.0-3216 while latest couchbase-transactions-1.0.0-alpha.3.jar dowloaded from (https://hub.internal.couchbase.com/confluence/pages/viewpage.action?spaceKey=SDK&title=Transactions ).

Based on logs It looks like transactions are failing  while creating/retrieving Subdoc's . Not sure its a SDK/Server kv issue . Please take a look at the detailed logs attached 

 

Please find implementation details and SDK/transaction logs (attached) .

 

YCSB Implementation details in github - 

https://github.com/couchbaselabs/YCSB/tree/couchbase3-transactions-playground

 

Error Snippet -

 "Transaction logger:14/Thread-1/257f6fd1-75d8-4969-a40f-ddc2b839975c starting attempt 3/026fae55-b851-4ebd-86b7-65fbd04c1139

Transaction logger:14/Thread-1/257f6fd1-75d8-4969-a40f-ddc2b839975c/026fae55-b851-4ebd-86b7-65fbd04c1139 getting doc usertable:user6873002678636213555

_Transaction logger:14/Thread-1/257f6fd1-75d8-4969-a40f-ddc2b839975c/026fae55-b851-4ebd-86b7-65fbd04c1139 caught exception 'com.couchbase.client.core.error.RequestTimeoutException: SubdocGetRequest {"retried":13,"reason":"TIMEOUT","requestId":23,"timeoutMs":2500,"service":

{"bucket":"bucket-1","type":"kv","key":"usertable:user6873002678636213555","cid":0}

,"cancelled":true,"coreId":1,"completed":true}' in asyncInternal, rethrowing to rollback_

"