Operations

What is Sticky Session?

A sticky session is a proxy configuration that pins your traffic to one exit IP for a fixed window instead of rotating on every request. You request it through a session identifier in the username or through a dedicated port, and the gateway routes each matching request back to the same node until the timer runs out.

The usual syntax is a parameter block inside the proxy username, something like customer-acc1-country-de-session-7f2c-sessTime-30, where the last field asks for thirty minutes on one address. Vendors differ on vocabulary, with sessid, sticky and session-duration all in circulation. The mechanism underneath is identical, since a string you control becomes the routing key. Providers publish a maximum, often minutes for residential pools and hours or open-ended for mobile lines where you hold the modem. Asking for more than the ceiling tends to clamp you to it rather than raise an error.

Stickiness is best effort on shared infrastructure. The device behind your session can go offline or be rotated by the carrier, and the gateway then has to hand you something else or fail the request. Read the provider's documented behaviour for that case. Some fall back to a new address transparently, which quietly breaks the account you were operating; others return a connection error so your code can decide what to do. Log the exit address either way, because an unrequested change dates the moment an account started failing.

Match the window to the work rather than to the provider's maximum. Logins, cart and checkout flows, anything that writes to an account, and any multi-step form need one address from first byte to last. Short windows of a minute or two suit paginated crawls where you want continuity across a few requests while still spreading load. Long windows raise exposure, because every request from that identity lands on one address, so a rate limit or a ban lands there too.

The term also lives in load balancing, where a sticky session means a front end sends a returning client back to the same backend server, usually through a cookie or a hash of the source IP. Same idea, opposite side of the wire. If you are reading server documentation and the sentence is about session affinity between application instances, it has nothing to do with which address your traffic exits from.

Where you meet it

You reach for a sticky session the moment a workflow carries state. Creating accounts, warming them, posting, checking an order, anything where the site remembers you between requests. In an antidetect browser you bind one profile to one sticky endpoint and leave it there; in a scraper you generate a session ID per worker and reuse it for the whole task. Random logouts and sudden verification prompts are the symptom of getting this wrong.

Common questions

How long can a sticky session hold the same IP?

Providers publish a maximum, from around a minute up to roughly thirty minutes on many residential pools, and considerably longer on mobile lines you control. Requesting more than the ceiling is usually clamped without warning. Treat the published number as a best case, since the device behind the address can drop at any point.

When should I use a sticky session instead of rotating?

Whenever the target remembers you between requests. Logins, checkout flows, form wizards, account creation and anything that posts content need one address from start to finish. Rotate for stateless reads such as product pages or search results, where each request stands alone and spreading load across addresses lowers the chance of a rate limit.

Do sticky sessions make requests slower?

Pinning itself adds no overhead. What it removes is the gateway's freedom to pick a faster node, so you get whatever that one device delivers for the whole window, including its bad minutes. On mobile the same line carries every request you send, so heavy parallel load on one sticky session raises latency for all of it.

Related terms

Session
In proxy usage, a session is a span of requests that all exit through the same IP address. It begins when you open a connection or claim a session identifier, and it ends when that identifier's timer expires or the network reassigns the address underneath you. Session control is what separates rotating traffic from a continuous identity.
IP Rotation
IP rotation is the practice of changing the outbound address a client uses, on every request, on a timer, or on demand. It spreads traffic so no single address builds up enough volume to be rate limited or banned, and it is the defining behaviour of rotating and backconnect proxy services.
Proxy Pool
A proxy pool is the set of IP addresses a provider can route your traffic through. Its usefulness comes from composition as much as from size: how many distinct subnets and autonomous systems it spans, how many countries it reaches, how heavily each address is reused, and how clean those addresses look to the sites you target.
Geotargeting
Geotargeting is choosing which country, region, city or carrier your proxy traffic exits from, so a site sees a visitor located where you want. You select it through parameters in the proxy username, a country-specific hostname, or a dedicated port, and the site reads that exit IP against whichever geolocation database it uses.
Geo-Restriction
Geo-restriction is a service limiting access or content by the visitor's apparent location. The site maps the client IP to a country through a geolocation database, then blocks the request or quietly swaps in a regional catalogue with local pricing. Content licensing, sanctions rules, tax registration and commercial strategy are the usual reasons.
Concurrent Connections
Concurrent connections are the number of proxy connections open at the same moment, counted across your workers rather than over a period. It is a capacity limit, separate from requests per second and from bandwidth. Ten connections can carry thousands of requests an hour when each is short, or almost none when each holds a slow page open.
Backconnect Proxy
A backconnect proxy is a single hostname and port that fronts a pool of many IP addresses. The client keeps one connection string while the provider's gateway assigns a different exit IP per request, per session or on a timer. Rotation and pool health checks happen upstream, where the client cannot see them.

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