Limits of WebSocket Protocol: A Guide

Introduction

Free services abound in the present-day world. Quite a few of them which are touted as free actually turn out not to be free. To accommodate professional traders, reputable centralized exchanges offer certain useful features. One of these is WebSocket protocol to monitor and interact with the latest market and user data. This protocol is a bidirectional communication tool. It is highly practical in approach, but to prevent the misuse of WebSocket Protocol, exchanges impose limits on how often and how long it can be used.

WebSocket Stream and WebSocket API

Most exchanges offer WebSocket API and WebSocket Stream. Both are bidirectional in that you can send as well as receive messages using the protocol. The stream is limited to market data only. You can view latest spot-traded prices and trades by using WebSocket Stream. If you want to buy and sell your assets by using the latest market data, WebSocket is the option for you.

Why Exchanges Impose Limits

It seems unfair on the part of exchanges to limit the use of a tool like WebSocket. However, when you see the reason, you admit that the imposition of limits is a justified act. These limits are meant to ensure stability, fairness and security in the platform. Multiplexing and multi-connections have the potential to overburden the system.

You might have come across a frequent prompt on the internet to prove that you are human. It proves that people use bots to surf and trade on the internet. Bots can overuse WebSocket protocol, leading to jamming of the network. This situation can lead to problems for common users. So, limits can prevent system from too many requests on the trot, which may contain malicious data.

Limits Imposed by Exchanges

1. Ping-Pong Mechanism

The first limit imposed by exchanges is that the WebSocket connection is terminated if there is no response within 10 minutes. The system sends you a ping every 3 minutes, which you must respond to within 10 minutes. Since WebSocket is a bilateral communication protocol, you can send messages on your own to acquire any data. But the ping must be responded to with a pong. Otherwise, the connection is terminated despite the fact that you have been communicating. A ping and a pong contain the same data and the same amount of it.

In short, normal communication does not replace the ping-pong mechanism. You must send a pong in response to WebSocket’s ping.

2. Connection and Stream Limit

In WebSocket Stream, you can establish one connection and subscribe to multiple streams in it. Alternatively, you can open different connections for different activities. Exchanges impose limits on both types of communication. When you view several streams side by side, there is a limit of 1024 of them per connection. This is quite a generous limit, which does not negatively affect any level of trading experience.

As for connections, there is a limit of 300 connections per IP address every 5 minutes. Just like the limit on streams, the connection limit is also more than enough for any crypto trader. The limits are in fact meant to stop an erroneous system or a bad actor from overloading the system. If there is a bug in the client’s computer, it may send numerous connection requests per second. Moreover, this can be done advertently by someone who desires to jam the system.

3. Rate and Weight Limits

Just as bad actors can try to overload the system by trying to connect again and again, some clients send too many messages too quickly. If it happens, the system blocks them temporarily. This limit is also targeted at keeping the network running smoothly.

Weight limits means that a client asks too much in one message. For example, if many symbols (BTC/USDT, ETH/USDT, XRP/USDT, etc.) are requested together, the system may feel the heat and ask the client to try again. There are not hard and fast limits on the rate and weight, but the user may learn it with experience.

WebSocket Errors and Solutions

1. Connection Closed

If it happens, the client can easily request connection again. The termination of connection can happen due to any violation of limits that have been mentioned above.

2. Connection Timed Out

Clients occasionally face this problem due to rate limit violation. A poor internet connection can also result in the same error. So, it is wise to check your connectivity if it happens.

3. Error 1000

If the server is closed due to any reason, the client can come across Error 1000. Simply, try to reconnect, and the problem is likely to be solved on its own.

4. Error 1008

Rate limit violation can lead to error 1008 and the client can be prompted to try again later. Waiting for a little while can solve this error.

How to Optimize User Experience

As with any system, problems can arise naturally. However, by following certain guidelines, you can make your experience free of hiccups. If you are a heavy user, you can opt to distribute your load to more than one server. Multiplexing and multi-connections still use the same server, so it is not likely to solve your problem. Furthermore, you should try to reuse your connections instead of making new ones so that you may save resources.

You should also double check your commands before sending them to the server. In case of any above-mentioned error, try after a while instead of trying again immediately. Also, try to keep your connection active by following the ping-pong rule. To avoid disconnection, review your rate and weight before starting the real communication.

Bottom Line

Although WebSocket protocol offered by Crypto exchanges offers generous thresholds, it is wise to keep the limits in mind while operating the network. As a successful crypto trader, you should know what kind of and how many errors you may face. When you acquire proper knowledge, you are able to sort out the issues arising from the usage.