Hi,
I believe background fill is enabled and tuned correctly for RWW.
we are trying to simulate the REFRESH MISS problem using a small local
setup.
we used 3 docker containers running on a single 4 core Intel Xeon CPU
E3-1220 v5 @ 3.00GHz machine as follows:
1) nginx origin using image nginx:alpine
2) ATS (built inside a container)
3) load using apache2-utils installed inside container python:3.7-alpine
inside the "load container" we run ab as follows: ab -k -n 500000 -c 4000
<url>
and sometimes we see one or 2 failed requests. we didn't find any 5XX
response in the ATS logs.
for every failed request reported by ab , we found 2 corresponding log lines
in ATS , a TCP_MISS_REDIRECT and a ERR_CONNECT_FAIL both with 303 response
code
"res_size_": "0", "origin_response_code_": "000", "response_code_": "303",
"response_time_": "7", "duration_": "0", "req_size_": "205",
"proxy_req_sz_": "377", "time_": "1593015615.000", "url_":
"http://ut-ats/collapse_fw/video/250kbit/seq-91.ts?test=527",
"orig_duration_": "0", "origin_": "ut-ngxorg", "origin_resp_sz_": "0",
"heirarchy_": "DIRECT", "crc": "TCP_MISS_REDIRECT"
"res_size_": "550","origin_response_code_": "000", "response_code_": "303",
"response_time_": "22", "duration_": "38", "req_size_": "155",
"proxy_req_sz_": "0", "time_": "1593015615.000", "url_":
"http://ut-ats/collapse_fw/video/250kbit/seq-91.ts?test=527",
"orig_duration_": "0", "origin_": "ut-ats",
"origin_resp_sz_": "0", "heirarchy_": "DIRECT", "crc": "ERR_CONNECT_FAIL"
--------------------------------------------------------------------------------
NGINX origin configuration:
we only added "max-age=1" header in the location section inside
/etc/nginx/conf.d/default.conf
and we ran a simple loop in the shell to touch the file that we are fetching
every 1 second
location / {
root /usr/share/nginx/html;
index index.html index.htm;
add_header Cache-Control "max-age=1, public";
}
--------------------------------------------------------------------------------
ATS configuration:
proxy.config.http.cache.open_write_fail_action 4
proxy.config.cache.enable_read_while_writer 1
proxy.config.http.redirection_enabled 1
proxy.config.http.number_of_redirections 10
proxy.config.http.redirect_use_orig_cache_key 1
proxy.config.http.background_fill_active_timeout 0
proxy.config.http.background_fill_completed_threshold 0
proxy.config.cache.max_doc_size 0
proxy.config.cache.read_while_writer.max_retries 10
proxy.config.cache.read_while_writer_retry.delay 50
proxy.config.http.cache.max_open_read_retries 5
proxy.config.http.cache.open_read_retry_time 10
proxy.config.http.wait_for_cache 1
proxy.config.http.cache.max_open_write_retries 1
map http://ut-ats/collapse_fw/ http://ut-ngxorg/assets/
@plugin=collapsed_forwarding.so @pparam=--delay=20 @pparam=--retries=2
--------------------------------------------------------------------------------
BR,
Erez
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