diff --git a/web/src/message_fetch.js b/web/src/message_fetch.js index 88067fbdac..d91205d73e 100644 --- a/web/src/message_fetch.js +++ b/web/src/message_fetch.js @@ -370,15 +370,29 @@ export function load_messages(opts, attempt = 1) { return; } - // Backoff on retries, with full jitter: up to 2s, 4s, 8s, 16s, 32s - let delay = Math.random() * 2 ** attempt * 2000; - if (attempt >= 5) { - delay = 30000; - } ui_report.show_error($("#connection-error")); + + // We need to respect the server's rate-limiting headers, but beyond + // that, we also want to avoid contributing to a thundering herd if + // the server is giving us 500s/502s. + // + // So we do the maximum of the retry-after header and an exponential + // backoff with full jitter: up to 2s, 4s, 8s, 16s, 32s + let backoff_delay_secs = Math.random() * 2 ** attempt * 2; + if (attempt >= 5) { + backoff_delay_secs = 30; + } + let rate_limit_delay_secs = 0; + if (xhr.status === 429 && xhr.responseJSON?.code === "RATE_LIMIT_HIT") { + // Add a bit of jitter to the required delay suggested by the + // server, because we may be racing with other copies of the web + // app. + rate_limit_delay_secs = xhr.responseJSON["retry-after"] + Math.random() * 0.5; + } + const delay_secs = Math.max(backoff_delay_secs, rate_limit_delay_secs); setTimeout(() => { load_messages(opts, attempt + 1); - }, delay); + }, delay_secs * 1000); }, }); } diff --git a/web/src/server_events.js b/web/src/server_events.js index b319c7e73e..cd5d7587e9 100644 --- a/web/src/server_events.js +++ b/web/src/server_events.js @@ -239,8 +239,21 @@ function get_events({dont_block = false} = {}) { } catch (error) { blueslip.error("Failed to handle get_events error", undefined, error); } - const retry_sec = Math.min(90, Math.exp(get_events_failures / 2)); - get_events_timeout = setTimeout(get_events, retry_sec * 1000); + + // We need to respect the server's rate-limiting headers, but beyond + // that, we also want to avoid contributing to a thundering herd if + // the server is giving us 500s/502s. + const backoff_delay_secs = Math.min(90, Math.exp(get_events_failures / 2)); + let rate_limit_delay_secs = 0; + if (xhr.status === 429 && xhr.responseJSON?.code === "RATE_LIMIT_HIT") { + // Add a bit of jitter to the required delay suggested + // by the server, because we may be racing with other + // copies of the web app. + rate_limit_delay_secs = xhr.responseJSON["retry-after"] + Math.random() * 0.5; + } + + const retry_delay_secs = Math.max(backoff_delay_secs, rate_limit_delay_secs); + get_events_timeout = setTimeout(get_events, retry_delay_secs * 1000); }, }); }