GraphQL execution slow and incorrect - graphql

Question

I have built my first GraphQL server in NodeJS to query a MySQL database using Sequelize and Apollo.
SQL commands run fast (as normal) but GraphQL queries are timing out, and returning incomplete data. So there are two issues I am facing:
Why is my GraphQL API querying so slowly?
How do I ensure I get all thedata that I need?
I have created a Stackblitz for this, and built a new test MySQL database. Unfortunately the stackblitz doesnt seem to be able to connect to a DB (either my real one or the test one, both work on my local version with the same code) but the structure is visible.
The GraphQL query I am trying to run is this:
query UnitTopicActivity($unitTopicActivityId: ID!) {
unitTopicActivity(id: $unitTopicActivityId) {
activity_id
activity_specific_id
id
topic_id
topic {
name
description
id
image
}
activity {
... on Working {
name
}
... on Experiment {
name
}
... on PhetLab {
name
}
... on VideoNote {
name
}
}
}
}
With variables
{
"unitTopicActivityId": 192
}
The output I expect is:
{
"data": {
"unitTopicActivity": {
"activity_id": 5,
"activity_specific_id": 44,
"id": "193",
"topic_id": 73,
"topic": {
"name": "Complex Energy Problems",
"description": "This is topic you will be required to use all you know of energy and work to solve some complex problems.",
"id": "73",
"image": ""
},
"activity": [ // not sure about what this should look like to be honest as I havent been able to generate it yet but this best guess.
{
"working": {
"name": "Working Activity"
}
},
{
"experiment": {
"name": "Experiment Activity"
}
}
]
}
}
}
What I get is (This single query takes 5.6 seconds):
{
"data": {
"unitTopicActivity": {
"activity_id": 5,
"activity_specific_id": 44,
"id": "193",
"topic_id": 73,
"topic": {
"name": "Complex Energy Problems",
"description": "This is topic you will be required to use all you know of energy and work to solve some complex problems.",
"id": "73",
"image": ""
},
"activity": null
}
}
}
If I try to run the query that does this for everyone of the items then I get some data but then a timeout in the code as it hits the execution limit in my database.js.
Edit - Some other info about similar querys:
This is a simple query and runs fast enough (631ms non local db for 165 rows), as expected:
query UnitTopicActivities {
unitTopicActivities {
activity_id
activity_specific_id
id
topic_id
}
}
If I add in the topic (thus a subquery to another table) then it gets about 50% of the stuff in the topic table the first time its queried and then is faster the next time:
query UnitTopicActivities {
unitTopicActivities {
activity_id
activity_specific_id
id
topic_id
topic {
id
name
description
image
}
}
}
Finally adding in the activity section produces the same results as originally provided, activity is null and it doesnt get through all the data before it times out.
end edit
I have tried to look up the issue elsewhere, and note that some people use another tool which stores data to speed up the process, but im not sure this is the solution. I dont think it should be this slow when the SQL command does it in under 0.1 seconds consistently and so expect there are other underlying issues.
Some things im not sure will help but I had been asked for in an unrelated context:
SHOW CREATE TABLE units_topics;
localhost/aM78gzT8nB/ https://remotemysql.com/phpmyadmin/db_sql.php?db=aM78gzT8nB
Your SQL query has been executed successfully.
SHOW CREATE TABLE units_topics
units_topics CREATE TABLE `units_topics` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `name` text NOT NULL,
 `description` text NOT NULL,
 `image` text NOT NULL,
 PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=74 DEFAULT CHARSET=latin1
SHOW TABLE STATUS WHERE name LIKE "units_topics";
localhost/aM78gzT8nB/ https://remotemysql.com/phpmyadmin/db_sql.php?db=aM78gzT8nB
Your SQL query has been executed successfully.
SHOW TABLE STATUS WHERE name LIKE "units_topics"
units_topics MyISAM 10 Dynamic 55 158 8700 281474976710655 2048 0 74 2022-12-01 11:00:21 2022-12-01 11:00:21
NULL
latin1_swedish_ci
NULL
The code is as follows:
server.js (launches an apollo server, this is the node launch file)
const apollo = require('#apollo/server');
const apolloStandalone = require('#apollo/server/standalone');
const gqlTools = require('#graphql-tools/merge');
const playGround = require('apollo-server-core');
const schema = [require('./schema/minimumSchema')];
const typeDefs = gqlTools.mergeTypeDefs(...[schema.map((a) => a.typeDefs)]);
const resolvers = gqlTools.mergeResolvers(...[schema.map((a) => a.resolvers)]);
// server function (async bug?)
async function startApolloServer(typeDefs, resolvers) {
// create an apollo serve rinstance...
const server = new apollo.ApolloServer({
typeDefs,
resolvers,
plugins: [playGround.ApolloServerPluginLandingPageGraphQLPlayground()],
});
const { url } = await apolloStandalone.startStandaloneServer(server, {
listen: { port: 4000 },
});
console.log(`🚀 Server ready at: ${url}`);
}
startApolloServer(typeDefs, resolvers);
database.js - this links to the database. Username, password etc left in as itsa temporary test server.
const Sequelize = require('sequelize');
const graphql = require('graphql/type');
var db = {};
const Date = new graphql.GraphQLScalarType({
name: 'Date',
description: 'Date custom scalar type',
serialize(value) {
return value.getTime(); // Convert outgoing Date to integer for JSON
},
parseValue(value) {
return new Date(value); // Convert incoming integer to Date
},
parseLiteral(ast) {
if (ast.kind === Kind.INT) {
// Convert hard-coded AST string to integer and then to Date
return new Date(parseInt(ast.value, 10));
}
// Invalid hard-coded value (not an integer)
return '1';
},
});
const sequelize = new Sequelize.Sequelize(
'aM78gzT8nB',
'aM78gzT8nB',
'RtPJ3fI68F',
{
host: 'remotemysql.com',
port: '3306',
dialect: 'mysql',
dialectModule: require('mysql2'),
logging: false,
pool: {
max: 2,
min: 0,
acquire: 30000,
idle: 20000,
},
}
);
let models = [
require('./models/a_experiment'),
require('./models/a_flashcards'),
require('./models/a_phetlabs'),
require('./models/a_videonotes'),
require('./models/a_working'),
require('./models/units_topics'),
require('./models/units_topics_activities'),
];
models.forEach((model) => {
const seqModel = model(sequelize, Sequelize.Sequelize);
db[seqModel.name] = seqModel;
});
Object.keys(db).forEach((key) => {
if ('associate' in db[key]) {
db[key].associate(db);
}
});
db.sequelize = sequelize;
db.Sequelize = Sequelize.Sequelize;
module.exports = db;
module.exports.Date = Date;
minimumSchema.js is the file I have defined the types and resolvers in:
const db = require('../database');
const typeDefs = `
type Experiment {
id: ID!
points_max: Int
name: String
introduction: String
diagram_link: String
}
type Flashcard {
id: ID!
topic_id: Int
side_a: String
side_b: String
topic: Topic
}
type PhetLab {
id: ID!
name: String
description: String
embed_code: String
sim_link: String
points_max: Int
}
type VideoNote {
id: ID!
points_max: Int
name: String
link: String
length: Int
}
type Working {
id: ID!
points_max: Int
name: String
description: String
}
type Topic {
id: ID!
name: String
description: String
image: String
}
union Activity = Working | Experiment | PhetLab | VideoNote
type Query {
unitTopicActivities(query: String): [UnitTopicActivity]
unitTopicActivity(id: ID!): UnitTopicActivity
}
type UnitTopicActivity {
id: ID!
topic_id: Int
activity_id: Int
activity_specific_id: Int
topic: Topic
activity: [Activity]
}
`;
const resolvers = {
Query: {
unitTopicActivities: async (obj, args, context, info) =>
db.units_topics_activities.findAll(),
unitTopicActivity: async (obj, args, context, info) =>
db.units_topics_activities.findOne({ where: { id: args.id } }),
},
UnitTopicActivity: {
topic: async (obj, args, context, info) =>
db.units_topics.findOne({ where: { id: obj.topic_id } }),
activity: async (obj, args, context, info) => {
switch (obj.activity_id) {
case 1:
db.a_videonotes.findByPk(obj.activity_specific_id);
break;
case 2:
db.a_experiment.findByPk(obj.activity_specific_id);
break;
case 3:
db.a_phetlabs.findByPk(obj.activity_specific_id);
break;
case 5:
db.a_working.findByPk(obj.activity_specific_id);
break;
}
},
},
Flashcard: {
topic: async (obj, args, context, info) =>
db.units_topics.findOne({ where: { id: obj.topic_id } }),
},
};
module.exports.resolvers = resolvers;
module.exports.typeDefs = typeDefs;
Then the models - these are the files sequelize uses so it knows what the database looks like:
The first five, experiment, working, flashcards, phetlabds and videonotes just store the activity names, the descriptions and the points required. Some other basic info and they are all a little different but basically all server the same purpose and arent usually queried on their own.
a_experiment.js
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('a_experiment', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
points_max: {
type: DataTypes.INTEGER,
allowNull: false,
defaultValue: 100
},
name: {
type: DataTypes.TEXT,
allowNull: false
},
introduction: {
type: DataTypes.TEXT,
allowNull: false
},
diagram_link: {
type: DataTypes.TEXT,
allowNull: false
}
}, {
sequelize,
tableName: 'a_experiment',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
a_flashcards.js
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('a_flashcards', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
topic_id: {
type: DataTypes.INTEGER,
allowNull: false
},
side_a: {
type: DataTypes.TEXT,
allowNull: false
},
side_b: {
type: DataTypes.TEXT,
allowNull: false
}
}, {
sequelize,
tableName: 'a_flashcards',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
a_phetlabs.js
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('a_phetlabs', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
name: {
type: DataTypes.TEXT,
allowNull: false
},
description: {
type: DataTypes.TEXT,
allowNull: false
},
embed_code: {
type: DataTypes.TEXT,
allowNull: false
},
sim_link: {
type: DataTypes.TEXT,
allowNull: false
},
points_max: {
type: DataTypes.INTEGER,
allowNull: false
}
}, {
sequelize,
tableName: 'a_phetlabs',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
a_videonotes.js
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('a_videonotes', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
points_max: {
type: DataTypes.INTEGER,
allowNull: false,
defaultValue: 100
},
name: {
type: DataTypes.TEXT,
allowNull: false
},
link: {
type: DataTypes.TEXT,
allowNull: false
},
length: {
type: DataTypes.INTEGER,
allowNull: false
}
}, {
sequelize,
tableName: 'a_videonotes',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
a_working.js
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('a_working', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
points_max: {
type: DataTypes.INTEGER,
allowNull: false,
defaultValue: 100
},
name: {
type: DataTypes.TEXT,
allowNull: false
},
description: {
type: DataTypes.TEXT,
allowNull: false
}
}, {
sequelize,
tableName: 'a_working',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
units_topics.js - This lists the topics, with their names, descriptions etc. Again this is unlikely the be queries on its own:
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('units_topics', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
name: {
type: DataTypes.TEXT,
allowNull: false
},
description: {
type: DataTypes.TEXT,
allowNull: false
},
image: {
type: DataTypes.TEXT,
allowNull: false
}
}, {
sequelize,
tableName: 'units_topics',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
units_topics_activities.js - This is the table that is likely to be queried, and pulls together the topics and the activities from any of the five different activity databases. Its a link between the topicId and the activityIds.
const Sequelize = require('sequelize');
module.exports = function(sequelize, DataTypes) {
return sequelize.define('units_topics_activities', {
id: {
autoIncrement: true,
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true
},
topic_id: {
type: DataTypes.INTEGER,
allowNull: false
},
activity_id: {
type: DataTypes.INTEGER,
allowNull: false
},
activity_specific_id: {
type: DataTypes.INTEGER,
allowNull: false
}
}, {
sequelize,
tableName: 'units_topics_activities',
timestamps: false,
indexes: [
{
name: "PRIMARY",
unique: true,
using: "BTREE",
fields: [
{ name: "id" },
]
},
]
});
};
Finally there the init-models.js file which simply initialises the database structures in sequelize:
var DataTypes = require('sequelize').DataTypes;
var _a_experiment = require('./a_experiment');
var _a_flashcards = require('./a_flashcards');
var _a_phetlabs = require('./a_phetlabs');
var _a_videonotes = require('./a_videonotes');
var _a_working = require('./a_working');
var _units_topics = require('./units_topics');
var _units_topics_activities = require('./units_topics_activities');
function initModels(sequelize) {
var a_experiment = _a_experiment(sequelize, DataTypes);
var a_flashcards = _a_flashcards(sequelize, DataTypes);
var a_phetlabs = _a_phetlabs(sequelize, DataTypes);
var a_videonotes = _a_videonotes(sequelize, DataTypes);
var a_working = _a_working(sequelize, DataTypes);
var units_topics = _units_topics(sequelize, DataTypes);
var units_topics_activities = _units_topics_activities(sequelize, DataTypes);
return {
a_experiment,
a_flashcards,
a_phetlabs,
a_videonotes,
a_working,
units_topics,
units_topics_activities,
};
}
module.exports = initModels;
module.exports.initModels = initModels;
module.exports.default = initModels;