Regrading distributed session among nodes

Your questions seems misleading in many respects:

• With "load balancer", do you mean Connection Load Balancer?
• Where do you see, from the query you issue, a node name? Connection Load Balancer tries to make sure that the connections to Vertica are evenly distributed across nodes.

If you mean Connection Load Balancing the way I put it above, try:
SELECT node_name, COUNT(*) AS session_count FROM user_sessions WHERE session_start_timestamp >= CURRENT_DATE::DATE GROUP BY 1;
... to check all nodes that have been used as the connection node today....

I mean to say number of queries are hitting to only one server. How i can manage this?

how do you see that the queries only hit one server? which query? Did you run the query I wrote above? and which is its output?

By "which query" , I mean , which query did you run to get the info that the queries only hit one server?

By this query
SELECT distinct node_name,count(*) FROM dc_requests_issued WHERE
date(time) >= date(sysdate()) group by 1;

2006 - Node1
3823 - Node2
3441- Node3

Result from below query
SELECT node_name, COUNT(*) AS session_count FROM user_sessions WHERE session_start_timestamp >= CURRENT_DATE::DATE GROUP BY 1;

896 - Node 3
1138 - Node 1
510 - Node 2

What is the output of below queries?
SELECT currentclientbalancingpolicy FROM vs_global_settings;
SELECT LOAD_BALANCE_POLICY FROM V_CATALOG.DATABASES;

It looks to quite some degree that we have a lot of clients that don't have ConnectionLoadBalancing=TRUE in the setup of their ODBC or JDBC connections. Or simply, vsql called without the "-C" switch to force connection load balancing.
This is my test:
$ for i in {1..3} ; do vsql -C -At -h 172.16.61.128 -u dbadmin -W passwd -d sbx_marco -c "select node_name from current_session"; done
v_sbx_marco_node0001
v_sbx_marco_node0002
v_sbx_marco_node0003

If you omit the "-C" switch, it will always be the first node ...

Hey SruthiA,

Roundrobin is result of both queries.

So dc_requests_issued (and with it, also the official query_requests system table, I'm sure) - returns this distribution:

2006 - Node1
3823 - Node2
3441- Node3

And user_sessions returns:

 896 - Node 3
1138 - Node 1
 510 - Node 2

Each query request issued originates from one session. So we had considerably more connections to node 1 , but they must have been idle (or sending long running, heavy queries) while nodes 2 and 3 got less connections. Node 2 issued the biggest number of queries from the lowest number of connections.

This is what your reports tell us. All 3 nodes are busy, albeit not in a perfectly balanced manner, but definitely no node is being left out.

What remains to clarify is where you now see a problem to which we should "suggest ASAP". Can you explain?

As you said,
All 3 nodes are busy, albeit not in a perfectly balanced manner, but definitely no node is being left out.
We want to balance in perfect manner.

Automatically, this is as good as it gets.
If you want to be a perfectionist, you would have to do that manually:
Connect to Vertica to check which node is least busy with sessions:
SELECT node_name,count(*) FROM sessions /* these are only the currently connected sessions */ GROUP BY 1 ORDER BY 2 LIMIT 1;
Collect the result , determine which IP address corresponds to the node name received, and connect to that node.
You will have a second-long connection to an unintended node (which might falsify the real connection balance a bit more), but you have a chance to balance the really active connections - those that keep firing queries ...

@hsaxena20,
What is your definition of "balance in perfect manner"? Exactly same number of connections on each node? That's meaningless!
Remember it is Load-Balancer and not connection-Balancer and from your metrics it seems load is perfectly balanced.
Thx