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Best Practices for API Error Handling

Posted on by Mario

Best-Practices-for-API-Error-Handling

As a web developer, we all don’t want to see Error codes in an API response, neither do you. When it happens to you, it can mean one of two things — there was something wrong in your request or your handling that the API simply couldn’t parse the passed data, or the API itself has so many problems. In either situation, traffic comes to a sudden end, and we start trying to discover the cause and solution for that.

Although being unpleasant, errors, whether in code form or simple error response, are incredibly useful. Error codes are probably the most useful diagnostic element in the API space.

Today, we’re going to discuss about the importance and the usefulness of error responses and handling approaches. There are some common error code classifications the average user will encounter, as well as some examples of these codes in action that you need to know.

The Value of Error Codes
As explained above, error codes are surprisingly, but incredibly useful. Error codes in the response stage of an API are essential in communicating failure from a developer to a user. This stage is a direct communication between client and API. It’s considered as the most important step towards informing the user of a failure, as well as boosting the error resolution process.

An error comes randomly and sometimes it’s beyond our knowledge. That’s why error responses are the only constant, consistent communication that we, as the user, can rely on when an error has occurred. Error codes can both clarify the situation, as well as communicate the intended functionality.

For example, an error code such as “401 Unauthorized – Please Pass Token.” You understand the point of failure in that response, especially that the user is unauthorized. However, you also figure out the intended functionality, which means that the API requires a token, and that token must be passed as part of the request in order to obtain authorization.

With a simple error code and resolution explanation, you have already identified the cause of the error, as well as the intended functionality and method to fix that error. It is very useful, especially for the amount of data that is actually returned.

HTTP Status Codes
Before we deeply discuss about error codes and what makes a code good, we need to sort out the HTTP Status Codes format. These codes are the most frequent status codes that the average user will encounter, not only in terms of APIs but also in terms of general internet usage. Although there are other protocols and have their own system of codes, the HTTP Status Codes dominate API communication, and vendor-specific codes tend to be derived from these ranges.

  • 1XX – Informational

The 1XX range has two basic functionalities. First, in the transfer of information concerning the protocol state of the connected devices — for example, 101 Switching Protocols is a status code noting that the client has requested a protocol change from the server, and that the request has been approved. The 1XX range also elucidates the state of the initial request. For example, 100 Continue, notes that a server has received request headers from a client, and that the server is waiting for the request body.

  • 2XX – Success

The 2XX range notes a range of successes in communication, and combines several responses into specific codes. The first three status codes excellently determine this range, like 200 OK means that a GET or POST request was successful, 201 Created indicates that a request has been brought to completion and a new resource has been created for the client, and 202 Accepted shows that the request has been accepted, and that processing has begun.

  • 3XX – Redirection

The 3XX range is all about the status of the resource or endpoint. When this kind of status code is sent, it confirms that the server is still accepting communication, but that the contacted point is not the accurate point of entry into the system. 301 Moved Permanently denotes that the client request did reach the correct system, but this request and all future requests should be managed by a different URI. This is very convenient both in subdomains and in moving a resource from one server to another.

  • 4XX – Client Error

The 4XX series of error codes is probably the most well-known because of the famous 404 Not Found status, which is a prominent marker for URLs and URIs that are formed in the wrong way. However, other more useful status codes for APIs are in this range.

414 URI Too Long is a common status code, indicating that the data pushed through in a GET request is too long, and should be changed into a POST request. Another common code is 429 Too many Requests, which is used for rate limiting to note a client is attempting too many requests simultaneously that their traffic is being rejected.

  • 5XX – Server Error

The 5XX range is reserved for error codes notably related to the server functionality. Whereas the 4XX range is the client’s responsibility (meaning that it is a client failure), the 5XX range explicitly notes failures with the server. Error codes such as 502 Bad Gateway, which marks the upstream server, has failed and that the current server is a gateway, further reveal server functionality as a method of showing where failure is transpiring.

Making a Good Error Code
With a strongly-built comprehension of HTTP Status Codes, we can start analyzing what actually makes for a good error code, and what makes for a bad error code. Quality error codes not only convey what went wrong, but also why it went wrong.

Excessively obscure error codes are very inconvenient. Imagine that you are trying to make a GET request to an API that manages digital music inventory. You’ve submitted your request to an API that usually accepts your traffic, you’ve passed the correct authorization and authentication credentials, and you think the server is ready to respond.

You send your data, and receive this kind of error code: 400 Bad Request. Without additional data and without more information, what does this mean? It’s in the 4XX range, so you know the problem was on the client side, but it doesn’t explain and solve anything, other than “bad request.”

This explains that a “helpful” error code is not as helpful as it should be. We could easily make that same response helpful and clear with less effort. Good error codes must pass three essential criteria in order to be functional, such as:

  • An HTTP Status Code, so that the source and realm of the problem can be confirmed with ease;
  • An Internal Reference IDfor documentation-specific notation of errors. In some cases, this can substitute the HTTP Status Code, as long as the internal reference sheet inserts the HTTP Status Code scheme or similar reference material.
  • Human readable messagesthat conclude the context, cause, and solution for the existing error.

From this discussion, we can conclude that error codes are useful if inserted with messages conveying what goes wrong and why it goes wrong, topped off with the human readable messages emphasizing the solution that we can take and do to handle it. That way, we can effortlessly handle it when future errors occur spontaneously.

Things that can be cached in WordPress Cache

Posted on by Mario

WordPress Cache What can be Cached and How We Do it

Caching is one of technologies which can contribute to site speed. Besides, caching will enable your stored data to be available for future requests. Some web developers might be familiar with it, some might not. But, if you haven’t been familiar with caching, you can learn more about it in this article. This article will explain what WordPress cache is and how it can be implemented on many different levels.

What is Caching?
In computing, the word “cache” is quite familiar. It refers to software or hardware component which is temporarily used to store values and retrieve them faster in the future. Values include MySQL queries, or compiled PHP bytecode as well as duplicate data, such as HTML and images.

In fact, we can gain a significant performance advantage by making copies of data and placing them in the “caching” component. This is because your visitors can retrieve cached content much faster than un-cached. Besides, your performance improvement can enhance depends on how much data that you can cache.

Things that can be cached
There are several levels, depending on how far you want to go in optimizing your website using caching. Here they are:

  • HTML Output
    You can find many plugins that can help you cache the HTML page itself. For instance, you can use WP Rocket and W3 Total Cache that can perform cache and many more. These plugins cache the result of the HTML output saving time for future requests. In fact, you can serve uncached content for every plugin have a cache invalidation mechanism.
    You can also try to “minify” HTML to make it smaller. This will add up a couple of kilobytes per page and keep increasing over time.
  • PHP OpCache
    A technique which PHP takes the source PHP files and compiles them into an intermediary form called bytecode is named OpCaching. Bytecode is like a computer’s machine code, but it refers to machine code that is executed by a “virtual machine” rather than by a real one. Fortunately, it can be executed quicker than having the PHP interpreter parse a command at a time since it is machine code and resides in memory.
    At a certain level, caching stores these bytecode data into memory, this causes your application gets executed faster. Besides, in order to have PHP OpCache enabled, you need to have access to the PHP configuration file.
  • PHP Object Cache
    This cache is done on the language’s OOP level. It uses the concept of “objects” to describe logic, data, and ideas. Objects are constantly being created and destroyed as your application runs. This technique solves the problem by caching the objects themselves.
    You can find PHP object cache in Memcached and the assorted ones for Redis. However, in order to enable PHP Object caching, you need to have access PHP configuration.
  • MySQL Query Caching
    The idea might be the same with PHP object cache, unless it is applied at a database level. A set of data are returned by the database based on the query that was entered. In fact, someone can get data much faster if someone has called the same data first. This is because they would reside cached in memory. But, you need to have access to the database server.

MySQL 5.7 Reference Manual

Posted on by Mario

My SQL

Nowadays, MySQL is the most popular database system used with PHP among so many developers. PHP combined with MySQL are cross-platform which you can develop in Windows and serve on a Unix platform. Basically, tables stores the data in a MySQL database. A table consists columns and rows which is a collection of related data. Databases are useful for storing information categorically. My SQL is an open source relational database management system (RDBMS).  So, whether you are a mobile or web developer, it is never too late to learn more about MySQL 5.7. Here are the details and don’t hesitate to check them out!

MySQL has supported for full-text indexing and searching, such as follows:

  • A full-text index in MySQL is an index of type FULLTEXT.
  • Only with InnoDB or MyISAM tables, you can create Full-text indexes, and can be created only for CHAR, VARCHAR, or TEXT
  • As of MySQL 5.7.6, My SQL provides a built-in full-text ngram parser. It supports Chinese, Japanese, and Korean (CJK), and an installable MeCab full-text parser plugin for Japanese. Parsing differences are outlined in Section 13.9.8, “ngram Full-Text parser”. Then, Section 13.9.9, “MeCab Full-Text Parser Plugin”.
  • CREATE TABLE provides A FULLTEXT index definition or adds later using ALTER TABLE orCREATE INDEX.
  • To load large data sets faster, you can use a table that has no FULLTEXT index. Then, create the index to load data into a table that has an existing FULLTEXT index.

By using  MATCH() … AGAINST syntax, you can perform full-text searching. MATCH() takes a comma-separated list that names the columns to be searched. You can use AGAINST to take a string and an optional modifier that indicates what type of search to perform. Create search string that is constant during query evaluation through string value. This rules out, for example, a table column because that can differ for each now.

There are three types of full-text searches:

  • A natural language search interprets search string as a phrase in natural human language. There are no special operators. The stop word list applies if the modifier gives or not give the IN NATURAL LANGUAGE MODE. Full-text searches are natural language searches.
  • Using the rules of a special query language, a Boolean search interprets the search string. The string contains the words to search for. It can also contain operators that specify requirements such that a word must be present or absent in matching rows. It also should be weighted higher or lower than usual. In Boolean search interprets, search index will omit certain common words. Besides, some words do not match if present in the search string. The IN BOOLEAN MODE modifier specifies a Boolean search.
  • A modification of a natural language search is a query expansion. To perform a natural language search, you can use search string. After adding the words to the search string, then words from the most relevant rows returned by the search. The search is done again. From the second search, the query returns the rows.