From 8ee4f308a47ea613a97493b8afbe1aed02f80036 Mon Sep 17 00:00:00 2001 From: Ben Busby Date: Wed, 10 Nov 2021 12:19:37 -0700 Subject: Prevent same instance from being selected twice in a row Introduces a new db key "-previous" to track which instance was last selected for a particular service. This allows for filtering the list of available instances to exclude the instance that was last picked, to ensure a (slightly) more even distribution of traffic. There's still the possiblity of the following scenario, however: :service instances > 2 /:service request #1 -> instance #1 /:service request #2 -> instance #2 /:service request #3 -> instance #1 /:service request #4 -> instance #2 where there are many ignored instances for a particular service. One possible solution would be to implement the "-previous" value to be a list, rather than a single value, and push to that list until only one element is left in the original "instance" array after filtering, and then delete the "-previous" key. --- config/config.exs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'config/config.exs') diff --git a/config/config.exs b/config/config.exs index 3b9dfe6..c522a9f 100644 --- a/config/config.exs +++ b/config/config.exs @@ -2,8 +2,9 @@ import Config config :farside, redis_conn: "redis://localhost:6379", - fallback_str: "-fallback", update_file: ".update-results", service_prefix: "service-", + fallback_suffix: "-fallback", + previous_suffix: "-previous", services_json: "services.json", index: "index.eex" -- cgit v1.2.3