Apropos Tech Solutions Corp. Blog

Category: servers

  • Web: proxy and reverse proxy, part0

    One hears about proxy and reverse proxy in the context of web servers. What are they, and why are they used?

    The following is by my understanding.

    A forward proxy server, or just proxy server, is a middleman: a request comes to it from a client, then the proxy sends along said request to the site that can fulfill it. The fulfillment site then sends its response back to the proxy, which forwards the response to the client.

    In the case of the proxy server, the fulfillment site thinks it’s interacting with the proxy; it doesn’t know about the client on the other side. Hence, the proxy can offer anonymity to the client, although the proxy itself knows all.

    A reverse proxy server is similar to a proxy server, but the client in this case is the fulfillment site. A web surfer sends a request to, they think, the fulfillment site. However, the request arrives to the fulfillment site’s proxy. Said proxy decides whether to pass the request along, and if so, to which specific port of the fulfillment site’s architecture.

    The requester, aka the web surfer, doesn’t know their request was processed by the reverse proxy.

    To its sponsor, the reverse proxy offers filtration of the incoming web requests. It sends each request to its appropriate destination, perhaps eliminating the bogus or dangerous requests.

    Source:

    Cloudflare. (2026). “What is a reverse proxy? Proxy servers explained.” https://www.cloudflare.com/learning/cdn/glossary/reverse-proxy/

    -js

  • Web: is my site on a LiteSpeed server? (Finding out from Firefox)

    Being on a LiteSpeed server, you can possibly use the LiteSpeed Cache.

    The following is by my understanding.

    Once a site gets busy, for instance a WordPress site, a cache can make the difference between the site being slow versus normal.

    On my oldest WordPress site, which went up in 2012, I have always used LiteSpeed Cache, except for a couple of interruptions during updates. When I had to run the site without it, I really noticed how much slower it loaded. On that site, LiteSpeed Cache is the only plugin I use. (See my post from June 5, 2026 for some background thoughts about plugins.)

    So, LiteSpeed Cache is a plugin that I like. However, as I understand, in order to use the LiteSpeed cache, one needs to be hosted on a LiteSpeed server. (Perhaps that’s a slight oversimplification, but likely good enough for a starter’s perspective.) How does one discover if they are?

    Here’s how I did so on Firefox:

    1. On a page from the site, right-click on a non-active part. From the drop-down, click Inspect.
    2. On the new pane that appears, find Network and click on it.
    3. Reload the page. A bunch of resources will be listed as they load.
    4. Click on any of the resources. A new pane will appear; on it, find Headers and click it.
    5. Underneath the Headers title, find Response Headers and scroll down. An entry like server: LiteSpeed indicates that, indeed, the site is on a LiteSpeed server.

    There are many potential directions to follow from this post. One motivation for finding if one’s on the LiteSpeed server is to discover whether using the LiteSpeed Cache is a possibility, perhaps even as a plugin if the site is WordPress.

    For follow-up I intend to mention corresponding directions relevant to Chrome and related browsers.

    Source:

    docs.litespeedtech.com

    w3.org

    -JS

  • Computer constructs: caches, part 0

    What is a cache? What are some types of them?

    The following is my understanding about caches.

    In French, cacher means “to hide.” However, in woods-person terms, “to hide” and “to store” are closely related, because storing food means hiding it from foragers. Hence, a cache is, functionally, a place to store stuff.

    In computer terms, a cache typically means a place where results are stored so the CPU doesn’t have to figure them out again. Rather, said responses can just be brought from storage immediately. Cache storage needs to be fast in order to effectively save time.

    Types of caches have evolved. They may be classified on how fast they are to retrieve from, as well as by what they store. In the web world, for instance, page caches store pre-built pages that are called for often. Object caches store answers to database queries, for instance, that are often requested. Opcode caches store parts of computer programs that are run often. In each case, the code has been refined into a finished solution, or closer to one, so the CPU doesn’t have to start from scratch to respond to a request.

    On a website that delivers complex content, such as a WordPress site might become, all three of the caches described above might be used. Typically, without a cache, the content may be delivered noticeably slower compared to when a cache is used. At high levels, caches can be calibrated to be even more efficient.

    Source:

    php.net: OPcache

    gxmediagy.com: “OPcache, Object Cache, and Page Cache: The Three Layers That Make Websites Feel Instant”

    -JS