Matchu
19f1ec092e
Well, instrumentation seems to be working fine again! The bug we ran into during commit e5081dab7e is gone. Cool!
I want to be able to see what's making the new box slow. My hypothesis was (and it seems to be right) that communication with the database on the Classic DTI server is slow.
But now that they're on the same Linode account and region, I think I can set up a private VLAN to make them muuuch faster. We'll try it out!
69 lines
3 KiB
JavaScript
69 lines
3 KiB
JavaScript
const beeline = require("honeycomb-beeline")({
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writeKey: process.env["HONEYCOMB_WRITE_KEY"],
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dataset:
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process.env["NODE_ENV"] === "production"
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? "Dress to Impress (2020)"
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: "Dress to Impress (2020, dev)",
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serviceName: "impress-2020-gql-server",
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samplerHook,
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});
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const { ApolloServer } = require("../../src/server/lib/apollo-server-vercel");
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const { config } = require("../../src/server");
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const crypto = require("crypto");
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const server = new ApolloServer(config);
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const serverHandler = server.createHandler();
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// We apply different sampling rates for different GraphQL operations
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// (according to the client-defined query name), depending on how much load
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// we're getting on them. For most operations, we just save all the events, but
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// especially heavy-load operations get a lower sampling rate!
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const OPERATION_SAMPLE_RATES = {
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ApiOutfitImage: 10, // save 1 out of every 10, ignore the others
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SearchPanel: 5, // save 1 out of every 5, ignore the others
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};
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function samplerHook(data) {
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// Use the sample rate from the table above.
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// Defaults to 1 (all) for most operations.
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let sampleRate = OPERATION_SAMPLE_RATES[data["app.operation_name"]] || 1;
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// Use the `deterministicSampler` to decide whether this event should be
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// sampled. This might be a child event of a higher-level trace, and we want
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// to make sure that we always return all child events of traces we've
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// sampled, and no child events of traces we haven't. Deterministically
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// sampling by trace ID does this for us!
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//
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// This strategy is outlined in: https://docs.honeycomb.io/getting-data-in/javascript/beeline-nodejs/#sampling-events.
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const shouldSample = deterministicSampler(data["trace.trace_id"], sampleRate);
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return { shouldSample, sampleRate };
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}
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function deterministicSampler(traceId, sampleRate) {
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// Copied from https://docs.honeycomb.io/getting-data-in/javascript/beeline-nodejs/#sampling-events
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const MAX_UINT32 = Math.pow(2, 32) - 1;
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const sum = crypto.createHash("sha1").update(traceId).digest();
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const upperBound = (MAX_UINT32 / sampleRate) >>> 0;
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return sum.readUInt32BE(0) <= upperBound;
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}
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async function handle(req, res) {
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// CAREFUL! We here allow any website to use our GraphQL API, so our data can
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// be more useful to the public. Using the * wildcard means that, in modern
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// browsers, requests should be sent without credentials. Additionally, we
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// don't store credentials in cookies; the client is responsible for setting
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// an Authorization header. So, I don't think there's any CSRF danger here.
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// But, let's be careful and make sure this continues to be true!
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res.setHeader("Access-Control-Allow-Origin", "*");
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await serverHandler(req, res);
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// As a sneaky trick, we require the Honeycomb trace to finish before the
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// request formally finishes. This... is technically a slowdown, I'm not sure
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// how much of one. Hopefully not too much?
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// https://vercel.com/docs/platform/limits#streaming-responses
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await beeline.flush();
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res.end();
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}
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export default handle;
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