ops
d380db741b
ssb-viewer holds one muxrpc handle captured in a closure and has no reconnect path. When sbot is OOM-killed and restarted by run-server.sh, the viewer kept port 8807 open while holding a dead connection and never answered again -- the silent wedge. Listen for muxrpc closed and exit(1) so the while-loop in run-ssb-viewer.sh restarts with a fresh connection. Also poll whoami to catch half-open connections where closed never fires. Verified: killing sbot now self-heals in ~4s instead of hanging.
50 lines
1.9 KiB
JavaScript
Executable File
50 lines
1.9 KiB
JavaScript
Executable File
#!/usr/bin/env node
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// ssb-viewer connects to sbot exactly once and hands the handle to index.js,
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// which captures it in a closure behind http.createServer().listen(). There is
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// no reconnect. So when sbot dies -- which on this box means "gets OOM-killed",
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// after which run-server.sh restarts it -- the viewer keeps port 8807 open
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// while holding a dead muxrpc connection, and never answers another request.
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//
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// That is the silent wedge. The fix is not to reconnect (index.js can't take a
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// new handle) but to exit loudly, so the `while true` loop in run-ssb-viewer.sh
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// restarts us with a fresh connection.
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var PING_INTERVAL_MS = 60000
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var PING_TIMEOUT_MS = 20000
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function bail (why) {
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console.error('[viewer] ' + new Date().toISOString() + ' ' + why + ' — exiting so the run loop restarts us')
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process.exit(1)
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}
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require('ssb-client')(function (err, sbot, config) {
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// ssb-client already wraps this as "could not connect to sbot", so don't
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// prefix it again.
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if (err) return bail(String(err.message || err))
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// muxrpc emits 'closed' when the underlying stream ends
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// (see node_modules/muxrpc/index.js). This is the fast path.
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sbot.on('closed', function () {
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bail('sbot connection closed')
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})
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// Belt and braces: a half-open TCP connection can leave 'closed' unfired
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// while calls silently hang forever. Poll a cheap RPC to catch that case.
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if (typeof sbot.whoami === 'function') {
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var timer = setInterval(function () {
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var timeout = setTimeout(function () {
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bail('sbot did not answer whoami within ' + (PING_TIMEOUT_MS / 1000) + 's')
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}, PING_TIMEOUT_MS)
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sbot.whoami(function (err) {
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clearTimeout(timeout)
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if (err) bail('sbot whoami failed: ' + (err.message || err))
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})
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}, PING_INTERVAL_MS)
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// Don't hold the event loop open on our account.
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timer.unref()
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}
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require('.').init(sbot, config)
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})
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