add overall api client rate limit option

[creharmony]

As Etsy limits the number of call per time window,

It would be great to have an option to calibrate client calls rate limit to never reach allowed api key rate limit.

• option must be disabled by default
• option must be configured by options
• options must permit "per second" and/or "per day" windows
• study retry after option in case of error (another issue to implement retry?)

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• Etsy rate limit documentation

[boly38]

• rate limiter without shared storage will not scale up
• request-rate-limiter - pro : top seo, very easy to implement // con : embeds experimental-modules, enforce "module" type
• node-rate-limiter - pro : very easy to implement // con : ?

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node rate limiter

• using promise : cf. /How to use rate limiter and retrieve my business method result jhurliman/node-rate-limiter#68

[boly38]

node-rate-limiter - Intensive Etsy calls with a rate limit set to 10/sec makes some etsy error as result:

You have exceeded your quota of: 10 requests per 1 second(s) for public requests.

So following this, I made some additional test :

                              duration =~ average rate
    200 queries at 10/sec |=> 19sec   =~ 10.52 /sec
    200 queries at  9/sec |=> 21.228  =~ 9.4215/sec
    200 queries at  8/sec |=> 24      =~ 8.33  /sec
    200 queries at  7/sec |=> 27.579  =~ 7.2519/sec
 

Intensive use of etsy client with a rate set to 8 or 7 per sec dont prevent etsy limit issue; maybe missing await?

Either Etsy or rate limiter is lying ;)

• tests show that rate limiter seems slightly upper contract

TODO

• create rate limiter issue => Limiter does not work jhurliman/node-rate-limiter#35
• try another library, or create a new library: => Create very first version susi-rali#1

[creharmony]

• update susi-rali following should rate limit number of processing at a time susi-rali#3 maxProcessingPerWindow