SOCKET UTILIZATION IN NODE.JSAkhilesh Gupta

@agupta03

Inefficient use of TCP sockets: Is HTTP keep-alive working?

Node’s HTTP module supports keep-alive

But there is a catch!

TCP Connection kept alive only if PENDING requests in agent queue

If requests go out one-by-one Connection closed each time

High QPS/Low Latency

High time-wait sockets

Eventual node CRASH

Houston, we’ve had a problem here!

NPM Libraries to the rescue!

ceejbot/keep-alive-agent

mikeal/request : forever module

TBEDP/agentkeepalive

TUNING UP YOUR F-35!

Monitor time_wait sockets !

“If you can’t measure it, you can’t fix it”

TUNING UP YOUR F-35!

maxSockets !

Concurrent sockets agent can have open/host

TUNING UP YOUR F-35!

idleTimeout !

Time for which connection is unused before it is discarded

THE ENGINEERING HAPPINESS GRAPH

Normal agent:

Transactions: 60000 hits!Availability: 100.00 %!Elapsed time: 46.53 secs!Data transferred: 14.88 MB!Response time: 0.05 secs!Transaction rate: 1289.49 trans/sec!Throughput: 0.32 MB/sec!Concurrency: 59.81!Successful transactions:60000!Failed transactions: 0!Longest transaction: 0.45!Shortest transaction: 0.00

Keep alive agent (30 seconds):

Transactions: 60000 hits!Availability: 100.00 %!Elapsed time: 29.70 secs!Data transferred: 14.88 MB!Response time: 0.03 secs!Transaction rate: 2020.20 trans/sec!Throughput: 0.50 MB/sec!Concurrency: 59.84!Successful transactions:60000!Failed transactions: 0!Longest transaction: 0.15!Shortest transaction: 0.01

TUNING UP YOUR F-35!

Upgrade to Node 0.5.3+ !

Agent holds sockets for any number of hosts