GeoServer WMS meta-tile is often recommended to be used to overcome problems such as:
I just need some clarification here: WMS meta-tile does not completely guarantee that such problems gone. WMS meta-tile only reduces them. Hence, in term of point symbols, symbols close to tile edges are still cutted but the occurrence of this is much reduced.
Is it right?
You are right that metatiles alone do not prevent cutting the symbols. In the picture below with 3x3 metatiles the inner star symbol will not be cut but the outer will because it is on the border of the metatile.
With symbols you can get a perfect result by using "gutter" parameter with a value that is bigger than half of the size of the biggest symbol. Read the usage from http://docs.geoserver.org/2.8.x/en/user/webadmin/tilecache/defaults.html
The gutter size sets the amount of extra space (in pixels) used when generating a tile. Use this in conjunction with metatiles to reduce problems with labels and features not being rendered incorrectly due to being on a tile boundary.
Labels are harder to handle because they might require very big gutter value and then double labels may appear because of automatic placement of labels.
Note: this "answer" is partially
(A) am going to share the result/answer as pointed by comments of my question,
(B) i need to show image not possible in comment, and
(C) maintain the flow of: question --> comment of question --> showing result.
@Andrea Aime, I tried the "buffer" parameter in WMS. It worked! Unfortunately I can not found examples/docs on how to use this "buffer" in WMS. The doc in http://docs.geoserver.org/latest/en/user/services/wms/vendor.html#buffer does not tell much about this. So I was just guessing, I placed "buffer" in the 3rd argument of a WMS definition in OpenLayers 2 (along with layer name, format, and style).
I tried 5 different scenarios of WMS tile, as illustrated below.
It seems that meta-tiled WMS alone (B) does not completely remove the "point symbol cut" artifact as stated by @user30184.
In my observation the WMS "buffer" parameter is enough in removing the artifact, either with "meta-tile" (C) or without "meta-tile" (D).
Single tile (E) not surprisingly does not have such artifact, also as prescribed by @user30184.
Based on this observation, with the aim of completely removing "symbol cut" artifact, i have 2 option : using buffer or using single tile. I am happy that i am not cornered with only single tile as my option.
