[2.1] Bots - reduce topic view updates

[sbulen]

This PR aims to minimize I/O during a bot attack by eliminating the tracking of guest & bot views in the smf_topics record. Note this counter is incremented under all circumstances, and causes yet another I/O during bot attacks.

An option is added, allowing the user to turn this behavior on or off. Users may wish to disable this only during high-CPU bot attacks.

I've been running this code on my prod forum with no issues.

If this is approved, I can submit a 3.0 version.

For more discussion see:
https://www.simplemachines.org/community/index.php?topic=592442.0

Feedback welcome.

[jdarwood007]

@sbulen Do you have the related updates for 3.0 on this PR?

[sbulen]

I was going to add 3.0 versions once the 2.1 ones were approved. Trying to avoid duplication of rework, etc.

This one has clear tradeoffs, but given there's a switch, folks can turn it on only when needed.

[jdarwood007]

This is another one: do we need to implement the installer/upgrader logic if the feature is disabled by default?

I've tagged this on the 3.0 project with the 2.1.8 milestone.

[Sesquipedalian]

Please remove unnecessary installer and upgrader changes.

[sbulen]

Please remove unnecessary installer and upgrader changes.

This is another one: do we need to implement the installer/upgrader logic if the feature is disabled by default?

I had deliberately set it up so behavior is unchanged if no var is found. Felt safest. Also, easiest to patch, no update needed.

But I did add to the installer & upgrader, mainly because I like seeing all the 'real' SMF vars doc'd in that fashion. To my knowledge, we've always added them.

I'll go either way, just letting you know my thoughts.

[Sesquipedalian]

There are already a number of other settings that aren't included in the install/upgrade scripts because they are disabled by default.

[sbulen]

OK, I'll remove.

[sbulen]

Done.

[jdarwood007]

Approved, will wait for a 3.0 version before I merge.