Lag

From MYSTlore

In online versions of Uru, lag describes the unpleasant symptom of a gameplay delays. With the exception of network latency, exact causes are mostly undocumented and up to explorers' speculation, though some analysis can be done even without any inside knowledge. Also, all issues have in common that they cannot be entirely eliminated; their extent (and thus, their degree of annoyance) can merely be minimized.

[edit] Network latency

This issue is mostly on the Internet connection's part, with the primary "solution" amounting to the explorer switching to a different Internet service provider, or at least to minimize other simultaneous uses of the network connection. It describes the amount of time it takes for a packet (a small unit of data sent over a network, such as the Internet) to travel from one endpoint to another, whereby, in Uru's context, Uru's auth, file and game servers make up one such endpoint, and every explorer's client makes up the other.

It manifests in numerous ways. For example:

[edit] "Teleporting"

When observing another avatar moving around, the following has to occur: the client from that other avatar (endpoint A) has to send information to the server (endpoint B) on what direction it is moving, and how (e.g., walking, running, jumping). The server (endpoint B) then has to forward this information to your own client (endpoint C), which in turn has to interpret it and, among other things, make it visually appear. This amounts to two distinct travels (from A to B, then from B to C) for every single change in movement. Depending on the two connections, this can easily make for a delay of a second, which, while sounding minuscule, is quite noticeable and, more importantly adds up.

To compensate, the server (B) and/or client (C) use strategies to predict movements to make up for lack of up-to-date information from the original client (A). For example, if an avatar presumably continues to walk into one particular direction, it will show up as such on C. Unfortunately, this can also go awry: if, in the meantime, the avatar has turned around, stopped movement, or started moving differently (e.g., by jumping or running), a "reset" effect will be quite visible: the avatar will at first seem to have moved somewhere, then "teleported" back and reset to its new "course". This looks unrealistic and, especially to those not familiar with the effect and its cause, quite strange.

[edit] Link-in lag

Link-in lag refers to the situation of witnessing another avatar (i.e., not yourself) linking in and having a delay of up to multiple seconds occur. In Myst Online: Uru Live, this is a very common phenomenon particularly in the Nexus-accessed instance of the city, e.g. in places such as the Ferry Terminal.

This kind of lag is presumably mostly on the client's side. One verifiable side-effect is the rapid increase in RAM use of the client process. This suggests that one of the main actions taken is to collect information about the avatar that has just linked in, such as the textures used for its face, hair and clothing, and to store the result in RAM. However, even with 2 GBs of RAM, this has been reported to be noticeable, suggesting that other factors contribute as well.

Typically not called link-in lag is a similar, but much more drastic effect of having to wait for what often amounts to several minutes before your own avatar actually links into an age. This, too, exists in several variants:

• If the client's loading screen displays a progress bar and a time remaining indicator, the latter will say "0 seconds remaining" for a long amount of time. In some extreme cases, the client will never recover from this state. This particular issue appears to be one of slow network connections, whereby the client fails to stay in sync with the server within a reasonable amount of time, and is therefore either "kicked out", or merely takes very long to establish the link.
• After the loading screen, the client's screen turns entirely black. It then, apparently, proceeds to fade into the Age's view. During or before this animation, the client can — temporarily or permanently — get "stuck". Like link-in lag of others, this particular problem is most-reported in the public city instance. Even with high-end configurations in terms of processor, memory, network connection, graphics, etc., this can amount to delays of a minute or more, with the explorer typically seeing nothing but an entirely black screen. There is no feedback or assurance of whether the client is doing something. However, some of the ambient sound noise may start appearing after a while long before the Age actually becomes visible.