What is a sticky session?

Most residential proxy services take the session in the proxy username, for example YOUR_USERNAME-session-cart01. The gateway maps each session name to an exit. The first connection with a new name gets an exit from the pool; later connections with the same name go out through it until the session duration ends or the IP leaves the pool. A different name asks for a different exit, though two names can land on the same one.

Residential exits are household connections, so a sticky IP can disappear early when the device goes offline or the ISP reassigns the address. Treat the duration as an upper bound, not a promise. Services also count it differently: from the first request, from the last, or in fixed clock windows, where a session that starts two minutes before a boundary keeps its IP for two minutes.

Pick by whether the steps of a job depend on each other.

A kept-alive connection stays on one exit even in rotating mode, so a test that reuses connections can make rotation look sticky. Rotating proxies vs sticky sessions covers rotation models and username forms.

A static proxy is an address assigned to you for the term you pay for, such as a datacenter IP or a static ISP address. It does not depend on a household device staying online, and when it is dedicated, nobody else sends traffic from it. A sticky session borrows an address from a shared pool for minutes or hours, then gives it back.

Choose static when a destination must see the same IP for days or weeks: a long-lived account, or an API that accepts only whitelisted addresses. Choose sticky when the flow lasts minutes to hours and the next one can start on a fresh residential IP.

A load balancer with sticky sessions, also called session affinity, sends every request from one client to the same backend server, usually by cookie or by hashing the client's IP. A proxy sticky session works at the other end of the connection: it keeps the IP the destination sees the same.

Set the session duration to the longest flow you run plus a margin, not to the most the service allows. A checkout that takes four minutes needs ten, not 24 hours. A longer session puts more requests on one IP and raises the chance that the household connection drops mid-flow.

Give each account, browser profile or job its own session name. One name reused across unrelated jobs puts them all on one IP.

Send the same session name to an IP echo service at an interval and log each exit with a timestamp. The point where the IP changes is the hold time you measured for that time of day:

lifetime-1800 asks for 30 minutes; leave it out on a service that has no session duration setting. Then run the real flow, because a site can stop answering one IP while that IP still works elsewhere.

The Proxy setup tab offers three session types: Rotating, Sticky and Sticky ports. Sticky adds -session- and a name of 1 to 32 letters or digits to the username, plus -lifetime- in seconds where the product accepts a session duration. Sticky ports suit tools that take one proxy per host and port: each port, SOCKS5 10000–10999 or HTTP 20000–20999, keeps one sticky IP for up to 24 hours while that IP stays available.

Sessions are best effort. On Residential IPv4, when one site stops answering through a sticky IP that still works elsewhere, the session keeps its IP and that connection gets No response; retry the request. The connection reference has the full syntax.