envoyproxy/envoy
GitHub で見るHow envoy instantiates HTTP filter? especially for lua filter.
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#27,117 opened on 2023年5月2日
area/luaenhancementhelp wanted
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説明
- Does each request create an instance per HTTP filter configured in the http_filters?
That is, for each request, the connection manager will create a C++ object of
Envoy::Extensions::HttpFilters::Lua::Filterclass (if it's configured in http_filters). - Is the same HTTP filter class allowed to be configured multiple times in http_filters? For example, this yaml specifies two configuration blocks for the same lua filter class. https://github.com/envoyproxy/envoy/blob/6e706d90b3c5a2947017c77d5bd209f16115dc8a/examples/lua/envoy.yaml#L38-L51
- Does each source code of lua filter have its own lua vm instance?
Each code block has its own thread-local lua state, i.e. each worker thread has one lua state.
https://github.com/envoyproxy/envoy/blob/6e706d90b3c5a2947017c77d5bd209f16115dc8a/source/extensions/filters/http/lua/lua_filter.h#L49
One config instance of lua filter has one default code block or code black map.
https://github.com/envoyproxy/envoy/blob/6e706d90b3c5a2947017c77d5bd209f16115dc8a/source/extensions/filters/http/lua/lua_filter.cc#L812-L826
So, for each worker thread, it has
<N>lua VM states, where<N>is the number of source code blocks configured?