Of course I forgot about the attachments ;-) Best wishes Jarek Bojar
----- Original Message ----- From: "Jaroslaw Bojar" <[email protected]> To: [email protected] Cc: "Mikołaj Gierulski" <[email protected]> Sent: Friday, October 19, 2012 3:45:29 PM Subject: Problem with chunked transfer encoding and short responses Hi, during evaluation of Haproxy for our internal loadbalancer we encountered following problem. Our backend sends very short responses (less than 1000 bytes). Transfer-encoding is set to chunked. Client connecting via haproxy experiences unexpectedly long delays (about 2-3 seconds) before receiving response. Larger responses (larger than about 1223 bytes) are received immediately. Obviously, when connecting to the backend directly, there is no such delay. We experienced this behaviour with three different backends (tomcat, weblogic and glassfish). We analyzed the communications with tcpdump and came to following conclusions: Haproxy seems to buffer the response received in several TCP packets, before sending it to the client (which is understandable). Delays described above happen when the whole response is received by haproxy (last chunk 0<CR><LF><CR><LF> is received) before it starts sending response to the client (probably response still fits some buffer). The whole response is sent to the client in one TCP packet. With longer responses haproxy sends response to the client in two or more TCP packets, and there is no delay before the last packet (when last chunk is received). We were able to workaround this problem with following solutions: - option http-no-delay - option http-server-close We read some discussions about similar problems (http://www.mail-archive.com/[email protected]/msg05419.html), but we find our situation different - we are not abusing http protocol. It's different, because we experience delays after the whole message was sent by the backend. Attached you will find our sample haproxy config file and tcpdump output. Best regards Jaroslaw Bojar & Mikolaj Gierulski -- Niniejsza wiadomość pochodzi z domeny @agora.pl, należącej do Grupy Kapitałowej Agory. Główne spółki wchodzące w skład Grupy Kapitałowej Agory to: Agora SA, ul. Czerska 8/10, 00-732 Warszawa; Numer identyfikacji podatkowej: PL 526-030-56-44; Miejsce zarejestrowania: Sąd Rejonowy dla m. st. Warszawy: Numer rejestru KRS: 59944; Kapitał zakładowy: 50.937.386 zł, wpłacony w całości. Agora - Poligrafia Sp. z o.o., ul. Towarowa 4, 43-110 Tychy; Numer identyfikacji podatkowej: PL 646-20-72-095; Miejsce zarejestrowania: Sąd Rejonowy w Katowicach Numer rejestru KRS: 72481; Kapitał zakładowy: 1.000.000,00 zł. Grupa Radiowa Agory Sp. z o.o., ul. Czerska 8/10, 00-732 Warszawa; Numer identyfikacji podatkowej: PL 521-289-70-03; Miejsce zarejestrowania: Sąd Rejonowy dla m. st. Warszawy Numer rejestru KRS: 126767; Kapitał zakładowy: 25.019.500,00 zł. Więcej informacji o spółkach na stronie: www.agora.pl Wiadomość jest przeznaczona wyłącznie dla zamierzonego adresata i może zawierać informacje o charakterze poufnym. W razie stwierdzenia, że odbiorcą miała być inna osoba prosimy poinformować nadawcę oraz niezwłocznie usunąć wiadomość. Wiadomość może nie stanowić oficjalnego stanowiska spółki Agora SA i nie być związana z jej działalnością. ------------ This message was sent from domain @agora.pl belonging to Agora Group. Principal companies in the Agora Group structure are: Agora SA, ul. Czerska 8/10, 00-732 Warszawa; Polish VAT and tax ID no.: PL 526-030-56-44; Place of registration: Regional Court for the Capital City of Warsaw; Registration no.: 59944; Share capital: PLN 50.937.386, fully paid-up. Agora - Poligrafia Sp. z o.o., ul. Towarowa 4, 43-110 Tychy; Polish VAT and tax ID no.: PL 646-20-72-095; Place of registration: Regional Court in Katowice; Registration no.: 72481; Share capital: PLN 1.000.000,00. Grupa Radiowa Agory Sp. z o.o., ul. Czerska 8/10, 00-732 Warszawa; Polish VAT and tax ID no.: PL 521-289-70-03; Place of registration: Regional Court for the Capital City of Warsaw; Registration no.: 126767; Share capital: PLN 25.019.500,00. For more information about our companies see site: www.agora.pl This message is for the intended recipient only and it may contain confidential information. If you receive this message in error, please immediately delete it and notify the sender. This message may not represent the official views of Agora SA and may not be related to its business.
tcpdump-jsp.tcp
Description: Binary data
haproxy.api.config
Description: Binary data
