503 Service Unavailable Error Through a Proxy

What the error means

The 503 code means “service unavailable”. It is temporary by nature: the server is running but cannot handle the request right now.

Our gateway's response is 503 NO_RAY: there is no free address for your geo parameters at the moment. If there is no name after the code, the 503 came from the site: it is overloaded, under maintenance or has limited your requests.

Causes

• The geo parameters are too narrow. Country, city and ISP together can leave very few addresses, especially in a small country.
• The chosen country has few addresses of this type. There are usually fewer mobile addresses than residential ones.
• The site is overloaded or under maintenance. Then it returns 503 to all visitors.
• The site limited your requests. Some sites answer 503 instead of 429 to requests that are too frequent.

How to fix it

1. On NO_RAY, widen the selection: remove the ISP, then the city, then try a neighboring country.
2. See how many addresses are online in the country you need on the locations page.
3. Retry the request in a few seconds: addresses come and go all the time.
4. If the 503 came from the site, open it without the proxy. If it is down that way too, all you can do is wait.
5. Lower the request rate and the number of threads to this site.

How to check that it works

Generate a line without a city and ISP and test it in the proxy checker. If everything works with wide parameters, the cause was a geo that was too narrow.