test: Prevent test_admin_ready_includes_schema_cache_state from timing out

By increasing the delays in this test by factor 400x, postgrest will not
swamp pg with connection retries after the failed schema cache anymore.

This would happen because there is no backoff included after fatal
errors. Once it does, the io tests hang indefinitely in CI.

src/PostgREST/SchemaCache.hs

@@ -145,6 +145,9 @@ type SqlQuery = ByteString
 
 querySchemaCache :: AppConfig -> SQL.Transaction SchemaCache
 querySchemaCache AppConfig{..} = do
+  _       <-
+    let sleepCall = SQL.Statement "select pg_sleep($1 / 1000.0)" (param HE.int4) HD.noResult prepared in
+    whenJust configInternalSCSleep (`SQL.statement` sleepCall) -- only used for testing
   SQL.sql "set local schema ''" -- This voids the search path. The following queries need this for getting the fully qualified name(schema.name) of every db object
   pgVer   <- SQL.statement mempty $ pgVersionStatement prepared
   tabs    <- SQL.statement schemas $ allTables pgVer prepared
@@ -155,9 +158,6 @@ querySchemaCache AppConfig{..} = do
   reps    <- SQL.statement schemas $ dataRepresentations prepared
   mHdlers <- SQL.statement schemas $ mediaHandlers pgVer prepared
   tzones  <- SQL.statement mempty $ timezones prepared
-  _       <-
-    let sleepCall = SQL.Statement "select pg_sleep($1)" (param HE.int4) HD.noResult prepared in
-    whenJust configInternalSCSleep (`SQL.statement` sleepCall) -- only used for testing
 
   let tabsWViewsPks = addViewPrimaryKeys tabs keyDeps
       rels          = addInverseRels $ addM2MRels tabsWViewsPks $ addViewM2OAndO2ORels keyDeps m2oRels

test/io/test_io.py

@@ -710,20 +710,23 @@ def test_admin_ready_includes_schema_cache_state(defaultenv, metapostgrest):
         **defaultenv,
         "PGUSER": role,
         "PGRST_DB_ANON_ROLE": role,
+        "PGRST_INTERNAL_SCHEMA_CACHE_SLEEP": "500",
     }
 
     with run(env=env) as postgrest:
-        # make it impossible to load the schema cache, by setting statement timeout to 1ms
-        set_statement_timeout(metapostgrest, role, 1)
+        # The schema cache query takes at least 500ms, due do PGRST_INTERNAL_SCHEMA_CACHE_SLEEP above.
+        # Make it impossible to load the schema cache, by setting statement timeout to 400ms.
+        set_statement_timeout(metapostgrest, role, 400)
 
         # force a reconnection so the new role setting is picked up
         postgrest.process.send_signal(signal.SIGUSR1)
-        sleep_until_postgrest_scache_reload()
+        # wait 600ms to finish schema cache reload attempt
+        time.sleep(0.6)
 
-        response = postgrest.admin.get("/ready")
+        response = postgrest.admin.get("/ready", timeout=1)
         assert response.status_code == 503
 
-        response = postgrest.session.get("/projects")
+        response = postgrest.session.get("/projects", timeout=1)
         assert response.status_code == 503
 
     reset_statement_timeout(metapostgrest, role)