Files
Eric Allam 7c95ee498e feat(webapp): tag Prisma spans with db.datasource attribute (#3422)
## Summary

Stamp every Prisma span with `db.datasource: "writer" | "replica"` so
traces can distinguish which client the query went through.

Both `PrismaClient` instances share the same global
`@prisma/instrumentation`, so their spans come out with identical names
and attributes today. This makes them trivially filterable.

## How

Two pieces in `apps/webapp/app/`:

1. **`v3/tracer.server.ts`** — a `DatasourceAttributeSpanProcessor`
reads an OTel context key in `onStart` and calls
`span.setAttribute("db.datasource", value)`. Registered as the first
span processor.
2. **`db.server.ts`** — `tagDatasource(datasource, client)` wraps each
`PrismaClient` with `$extends({ query: { $allOperations } })`. The
middleware sets the context key around the query and directly tags the
active span (to catch `prisma:client:operation`, which Prisma creates
before the middleware fires).

### Context-propagation gotcha

`PrismaPromise` is lazy — `query(args)` returns a thenable that only
starts when someone `.then()`s it. The naive `context.with(ctx, () =>
query(args))` restores ALS synchronously, so when Prisma's internal code
awaits the thenable later, the engine spans fire with the original ALS.
Wrapping as `async () => await query(args)` forces the `.then()` inside
the `context.with` callback, so ALS stays on our context for the engine
spans.

### Coverage

- **Tagged**: all `prisma:engine:*` (`connection`, `db_query`,
`serialize`, `query`, etc.), `prisma:client:operation`,
`prisma:client:serialize`, `prisma:client:connect`
- **Not tagged**: `prisma:client:load_engine` — one-time startup, fires
before any query

Concurrent `Promise.all([writer.x, replica.y])` correctly tags each pool
separately (ALS isolates per-Promise chain).

### Performance

One `context.with` (~200ns) and one `setAttribute` per span (effectively
free per OTel JS benchmarks) per Prisma op. Negligible against a query
path measured in milliseconds.

## Test plan

- [ ] Verify `db.datasource` appears on `prisma:engine:connection` spans
after the webapp is restarted
- [ ] Spot-check a handful of real traces carry the attribute
2026-04-21 16:56:17 +01:00

415 lines
11 KiB
TypeScript

import {
Prisma,
PrismaClient,
$transaction as transac,
type PrismaClientOrTransaction,
type PrismaReplicaClient,
type PrismaTransactionClient,
type PrismaTransactionOptions,
} from "@trigger.dev/database";
import invariant from "tiny-invariant";
import { z } from "zod";
import { env } from "./env.server";
import { logger } from "./services/logger.server";
import { isValidDatabaseUrl } from "./utils/db";
import { singleton } from "./utils/singleton";
import { DATASOURCE_CONTEXT_KEY, startActiveSpan } from "./v3/tracer.server";
import { context, Span, trace } from "@opentelemetry/api";
import { queryPerformanceMonitor } from "./utils/queryPerformanceMonitor.server";
export type {
PrismaTransactionClient,
PrismaClientOrTransaction,
PrismaTransactionOptions,
PrismaReplicaClient,
};
export async function $transaction<R>(
prisma: PrismaClientOrTransaction,
name: string,
fn: (prisma: PrismaTransactionClient, span?: Span) => Promise<R>,
options?: PrismaTransactionOptions
): Promise<R | undefined>;
export async function $transaction<R>(
prisma: PrismaClientOrTransaction,
fn: (prisma: PrismaTransactionClient) => Promise<R>,
options?: PrismaTransactionOptions
): Promise<R | undefined>;
export async function $transaction<R>(
prisma: PrismaClientOrTransaction,
fnOrName: ((prisma: PrismaTransactionClient) => Promise<R>) | string,
fnOrOptions?: ((prisma: PrismaTransactionClient) => Promise<R>) | PrismaTransactionOptions,
options?: PrismaTransactionOptions
): Promise<R | undefined> {
if (typeof fnOrName === "string") {
return await startActiveSpan(fnOrName, async (span) => {
span.setAttribute("$transaction", true);
if (options?.isolationLevel) {
span.setAttribute("isolation_level", options.isolationLevel);
}
if (options?.timeout) {
span.setAttribute("timeout", options.timeout);
}
if (options?.maxWait) {
span.setAttribute("max_wait", options.maxWait);
}
if (options?.swallowPrismaErrors) {
span.setAttribute("swallow_prisma_errors", options.swallowPrismaErrors);
}
const fn = fnOrOptions as (prisma: PrismaTransactionClient, span: Span) => Promise<R>;
return transac(
prisma,
(client) => fn(client, span),
(error) => {
logger.error("prisma.$transaction error", {
code: error.code,
meta: error.meta,
stack: error.stack,
message: error.message,
name: error.name,
});
},
options
);
});
} else {
return transac(
prisma,
fnOrName,
(error) => {
logger.error("prisma.$transaction error", {
code: error.code,
meta: error.meta,
stack: error.stack,
message: error.message,
name: error.name,
});
},
typeof fnOrOptions === "function" ? undefined : fnOrOptions
);
}
}
export { Prisma };
function tagDatasource<T extends PrismaClient>(
datasource: "writer" | "replica",
client: T
): T {
return client.$extends({
name: "datasource-tagger",
query: {
$allOperations: ({ query, args }) => {
trace.getActiveSpan()?.setAttribute("db.datasource", datasource);
return context.with(
context.active().setValue(DATASOURCE_CONTEXT_KEY, datasource),
async () => await query(args)
);
},
},
}) as unknown as T;
}
export const prisma = singleton("prisma", () => tagDatasource("writer", getClient()));
export const $replica: PrismaReplicaClient = singleton("replica", () => {
const replica = getReplicaClient();
return replica ? tagDatasource("replica", replica) : prisma;
});
function getClient() {
const { DATABASE_URL } = process.env;
invariant(typeof DATABASE_URL === "string", "DATABASE_URL env var not set");
const databaseUrl = extendQueryParams(DATABASE_URL, {
connection_limit: env.DATABASE_CONNECTION_LIMIT.toString(),
pool_timeout: env.DATABASE_POOL_TIMEOUT.toString(),
connection_timeout: env.DATABASE_CONNECTION_TIMEOUT.toString(),
application_name: env.SERVICE_NAME,
});
console.log(`🔌 setting up prisma client to ${redactUrlSecrets(databaseUrl)}`);
const client = new PrismaClient({
datasources: {
db: {
url: databaseUrl.href,
},
},
log: [
// events
{
emit: "event",
level: "error",
},
{
emit: "event",
level: "info",
},
{
emit: "event",
level: "warn",
},
// stdout
...((process.env.PRISMA_LOG_TO_STDOUT === "1"
? [
{
emit: "stdout",
level: "error",
},
{
emit: "stdout",
level: "info",
},
{
emit: "stdout",
level: "warn",
},
]
: []) satisfies Prisma.LogDefinition[]),
// Query performance monitoring
...((process.env.VERBOSE_PRISMA_LOGS === "1" ||
process.env.VERY_SLOW_QUERY_THRESHOLD_MS !== undefined
? [
{
emit: "event",
level: "query",
},
]
: []) satisfies Prisma.LogDefinition[]),
// verbose
...((process.env.VERBOSE_PRISMA_LOGS === "1"
? [
{
emit: "stdout",
level: "query",
},
]
: []) satisfies Prisma.LogDefinition[]),
],
});
// Only use structured logging if we're not already logging to stdout
if (process.env.PRISMA_LOG_TO_STDOUT !== "1") {
client.$on("info", (log) => {
logger.info("PrismaClient info", {
clientType: "writer",
event: {
timestamp: log.timestamp,
message: log.message,
target: log.target,
},
});
});
client.$on("warn", (log) => {
logger.warn("PrismaClient warn", {
clientType: "writer",
event: {
timestamp: log.timestamp,
message: log.message,
target: log.target,
},
});
});
client.$on("error", (log) => {
logger.error("PrismaClient error", {
clientType: "writer",
event: {
timestamp: log.timestamp,
message: log.message,
target: log.target,
},
ignoreError: true,
});
});
}
// Add query performance monitoring
client.$on("query", (log) => {
queryPerformanceMonitor.onQuery("writer", log);
});
// connect eagerly
client.$connect();
console.log(`🔌 prisma client connected`);
return client;
}
function getReplicaClient() {
if (!env.DATABASE_READ_REPLICA_URL) {
console.log(`🔌 No database replica, using the regular client`);
return;
}
const replicaUrl = extendQueryParams(env.DATABASE_READ_REPLICA_URL, {
connection_limit: env.DATABASE_CONNECTION_LIMIT.toString(),
pool_timeout: env.DATABASE_POOL_TIMEOUT.toString(),
connection_timeout: env.DATABASE_CONNECTION_TIMEOUT.toString(),
application_name: env.SERVICE_NAME,
});
console.log(`🔌 setting up read replica connection to ${redactUrlSecrets(replicaUrl)}`);
const replicaClient = new PrismaClient({
datasources: {
db: {
url: replicaUrl.href,
},
},
log: [
// events
{
emit: "event",
level: "error",
},
{
emit: "event",
level: "info",
},
{
emit: "event",
level: "warn",
},
// stdout
...((process.env.PRISMA_LOG_TO_STDOUT === "1"
? [
{
emit: "stdout",
level: "error",
},
{
emit: "stdout",
level: "info",
},
{
emit: "stdout",
level: "warn",
},
]
: []) satisfies Prisma.LogDefinition[]),
// Query performance monitoring
...((process.env.VERBOSE_PRISMA_LOGS === "1" ||
process.env.VERY_SLOW_QUERY_THRESHOLD_MS !== undefined
? [
{
emit: "event",
level: "query",
},
]
: []) satisfies Prisma.LogDefinition[]),
// verbose
...((process.env.VERBOSE_PRISMA_LOGS === "1"
? [
{
emit: "stdout",
level: "query",
},
]
: []) satisfies Prisma.LogDefinition[]),
],
});
// Only use structured logging if we're not already logging to stdout
if (process.env.PRISMA_LOG_TO_STDOUT !== "1") {
replicaClient.$on("info", (log) => {
logger.info("PrismaClient info", {
clientType: "reader",
event: {
timestamp: log.timestamp,
message: log.message,
target: log.target,
},
});
});
replicaClient.$on("warn", (log) => {
logger.warn("PrismaClient warn", {
clientType: "reader",
event: {
timestamp: log.timestamp,
message: log.message,
target: log.target,
},
});
});
replicaClient.$on("error", (log) => {
logger.error("PrismaClient error", {
clientType: "reader",
event: {
timestamp: log.timestamp,
message: log.message,
target: log.target,
},
});
});
}
// Add query performance monitoring for replica client
replicaClient.$on("query", (log) => {
queryPerformanceMonitor.onQuery("replica", log);
});
// connect eagerly
replicaClient.$connect();
console.log(`🔌 read replica connected`);
return replicaClient;
}
function extendQueryParams(hrefOrUrl: string | URL, queryParams: Record<string, string>) {
const url = new URL(hrefOrUrl);
const query = url.searchParams;
for (const [key, val] of Object.entries(queryParams)) {
query.set(key, val);
}
url.search = query.toString();
return url;
}
function redactUrlSecrets(hrefOrUrl: string | URL) {
const url = new URL(hrefOrUrl);
url.password = "";
return url.href;
}
export type { PrismaClient } from "@trigger.dev/database";
export const PrismaErrorSchema = z.object({
code: z.string(),
});
function getDatabaseSchema() {
if (!isValidDatabaseUrl(env.DATABASE_URL)) {
throw new Error("Invalid Database URL");
}
const databaseUrl = new URL(env.DATABASE_URL);
const schemaFromSearchParam = databaseUrl.searchParams.get("schema");
if (!schemaFromSearchParam) {
console.debug("❗ database schema unspecified, will default to `public` schema");
return "public";
}
return schemaFromSearchParam;
}
export const DATABASE_SCHEMA = singleton("DATABASE_SCHEMA", getDatabaseSchema);
export const sqlDatabaseSchema = Prisma.sql([`${DATABASE_SCHEMA}`]);