Sendgrid client doesn't close TCP connection properly

[bidhanadh]

Issue Summary

It is found that on most cases sendgrid-java client opens new connection to server but the http-connection close doesn't seem working properly which yields to TCP CLOSE_WAIT state living forever in program lifecycle. This accumulates many CLOSE_WAIT states on sending multiple emails.

Technical details:

• sendgrid-java Version: sendgrid-java version:3.1.0 [From maven-repo]
• Java Version: 1.8
• OS : Mac OS X

http log

Connection request: [route: {s}->https://api.sendgrid.com:443][total kept alive: 0; route allocated: 0 of 2; total allocated: 0 of 20]
Connection leased: [id: 0][route: {s}->https://api.sendgrid.com:443][total kept alive: 0; route allocated: 1 of 2; total allocated: 1 of 20]
Opening connection {s}->https://api.sendgrid.com:443
Connecting to api.sendgrid.com/119.81.43.4:443
Connecting socket to api.sendgrid.com/119.81.43.4:443 with timeout 0
Enabled protocols: [TLSv1, TLSv1.1, TLSv1.2]
Enabled cipher suites:[TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_DSS_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA, TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
Starting handshake
Secure session established
negotiated protocol: TLSv1.2
negotiated cipher suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
peer principal: CN=.api.sendgrid.com, OU=Domain Control Validated
peer alternative names: [.api.sendgrid.com, api.sendgrid.com]
issuer principal: CN=Go Daddy Secure Certificate Authority - G2, OU=http://certs.godaddy.com/repository/, O="GoDaddy.com, Inc.", L=Scottsdale, ST=Arizona, C=US
Connection established 192.168.55.189:56893<->119.81.43.4:443
Executing request POST /v3/mail/send HTTP/1.1
Proxy auth state: UNCHALLENGED
http-outgoing-0 >> POST /v3/mail/send HTTP/1.1
http-outgoing-0 >> Authorization: Bearer xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
http-outgoing-0 >> Accept: application/json
http-outgoing-0 >> User-agent: sendgrid/3.0.0;java
http-outgoing-0 >> Content-Type: application/json
http-outgoing-0 >> Content-Length: 237
http-outgoing-0 >> Host: api.sendgrid.com
http-outgoing-0 >> Connection: Keep-Alive
http-outgoing-0 >> Accept-Encoding: gzip,deflate
http-outgoing-0 >> "POST /v3/mail/send HTTP/1.1[\r][\n]"
http-outgoing-0 >> "Authorization: Bearer xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
http-outgoing-0 >> "Accept: application/json[\r][\n]"
http-outgoing-0 >> "User-agent: sendgrid/3.0.0;java[\r][\n]"
http-outgoing-0 >> "Content-Type: application/json[\r][\n]"
http-outgoing-0 >> "Content-Length: 237[\r][\n]"
http-outgoing-0 >> "Host: api.sendgrid.com[\r][\n]"
http-outgoing-0 >> "Connection: Keep-Alive[\r][\n]"
http-outgoing-0 >> "Accept-Encoding: gzip,deflate[\r][\n]"
http-outgoing-0 >> "[\r][\n]"
http-outgoing-0 >> "{"from":{"name":"xxxxxxx","email":"xxxxxxxxxxxxxx"},"personalizations":[{"to":[{"email":"xxxxxxxxxxxxxx"}],"substitutions":{"xxxxxxxxxxxxxx":"xxxxxxxxxxxxxx"}}],"template_id":"xxxxxxxxxxxxxxxxxxxxxxxxxxxx"}"
http-outgoing-0 << "HTTP/1.1 202 Accepted[\r][\n]"
http-outgoing-0 << "Server: nginx[\r][\n]"
http-outgoing-0 << "Date: Tue, 25 Oct 2016 00:20:35 GMT[\r][\n]"
http-outgoing-0 << "Content-Type: text/plain; charset=utf-8[\r][\n]"
http-outgoing-0 << "Content-Length: 0[\r][\n]"
http-outgoing-0 << "Connection: keep-alive[\r][\n]"
http-outgoing-0 << "X-Message-Id: EQd0l8CwSxixyIZepqG3QA[\r][\n]"
http-outgoing-0 << "X-Frame-Options: DENY[\r][\n]"
http-outgoing-0 << "[\r][\n]"
http-outgoing-0 << HTTP/1.1 202 Accepted
http-outgoing-0 << Server: nginx
http-outgoing-0 << Date: Tue, 25 Oct 2016 00:20:35 GMT
http-outgoing-0 << Content-Type: text/plain; charset=utf-8
http-outgoing-0 << Content-Length: 0
http-outgoing-0 << Connection: keep-alive
http-outgoing-0 << X-Message-Id: EQd0l8CwSxixyIZepqG3QA
http-outgoing-0 << X-Frame-Options: DENY
Connection can be kept alive indefinitely
Connection [id: 0][route: {s}->https://api.sendgrid.com:443] can be kept alive indefinitely
Connection released: [id: 0][route: {s}->https://api.sendgrid.com:443][total kept alive: 1; route allocated: 1 of 2; total allocated: 1 of 20]

TCP State

java 1654 xxxxxxxxx 178u IPv6 0x80cc5c0cfdc500ad 0t0 TCP 192.168.55.189:53928->42.70.5177.ip4.static.sl-reverse.com:https (CLOSE_WAIT)
java 1654 xxxxxxxxx 180u IPv6 0x80cc5c0cfdc4fb4d 0t0 TCP 192.168.56.1:53927->vm:postgresql (ESTABLISHED)
java 1654 xxxxxxxxx 181u IPv6 0x80cc5c0cfdc510cd 0t0 TCP 192.168.55.189:54111->4.2b.5177.ip4.static.sl-reverse.com:https (CLOSE_WAIT)

[thinkingserious]

Thanks @bidhanadh!

I've added this to our backlog for a fix.