improve HOL blocking and related protocol glossary entries #41525
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PassionPenguin
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| In HTTP/1.1, requests on a single {{glossary("TCP")}} connection are usually sent sequentially — a new request can't be made on the connection while waiting for a response to the previous request. | ||
| This can lead to HOL blocking problems even if there are several TCP connections between the client and server. | ||
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| A mechanism called _HTTP pipelining_ tried to work around this, where multiple requests were sent off by a client without waiting for any responses. | ||
| Pipelining proved tricky to implement in reality, so this mechanism is rarely used, if ever, and most browsers no longer support it. | ||
| HTTP/1.1 defines an optional feature called _HTTP pipelining_ that unsuccessfully attempted to work around HOL blocking, by allowing requests to be sent without waiting for earlier responses. | ||
| Unfortunately the design of HTTP/1.1 means that responses must be returned in the same order as the requests were received, so HOL blocking can still occur if a request takes a long time to complete. | ||
| Network conditions such as congestion, packet loss (and the resulting TCP retransmissions), or {{glossary("TCP slow start")}} can also delay transmission and cause later responses to be blocked by earlier ones. |
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@PassionPenguin I think this works as an English fix. Are you happy with it?
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sure that's good! thanks!
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