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Questions tagged [keepalive]

The tag has no usage guidance.

0
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0answers
16 views

tcp keepalive doesn't receive response but didn't retry to send another keepalive

I am using linux kernel 2.6.32 with tcp keepalive enable, and normally keepalive works fine, but when the kernel send keepalive packets within 10ms send another data packet[SIP register packet], the ...
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0answers
20 views

How to detect and recover from TCP socket blackholes more quickly?

Our problem is that we occasionally get into a state where our sockets turn into blackholes, i.e., we are sending data to the socket, but it never reaches its destination and there is no notification ...
0
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0answers
44 views

Request with Keep-Alive freezes ngnix when issued twice

I have a 3 docker container configuration, NGINX, php-fpm and a mysql db. A request I just added, which involves sending a ~80kb png across HTTP causes nginx to freeze and neither complete the request ...
2
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0answers
58 views

TCP KeepAlives with NAT?

We have a Network set up like this: MQTT Client -- TCP Forward (Netscaler) -- TLS Termination + TCP Forwarding (HAProxy) -- MQTT Server For several reasons we needed to turn on TCP KeepAlives in ...
0
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0answers
32 views

keep-alive “graphical” utilities wiithout RDP connection on Windows Server

I have to send keyboard input and mouse activity detection to an application on my Windows Server. I use SendKeys.SendWait to do so. It works perfectly when a RDP connection is active, and it keeps ...
0
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1answer
725 views

AWS API Gateway with Lambda and KeepAlive (persistent connections)

I'm a bit confused about Keep-Alive with AWS API Gateway. Is this something I need to configure? or maybe be careful with this setting? Because I will use API Gateway to execute Lambda functions, and ...
0
votes
1answer
2k views

Difference between keepalive in apache2.conf and in ProxyPass

I am using Apache 2.2.22 What is the difference, if there is any, between the Keepalive directive in /etc/apache2/apache2.conf # # KeepAlive: Whether or not to allow persistent connections (more ...
2
votes
1answer
201 views

git push fails - permissions and ssh keep alive checked - what else?

I migrated my git server to a new server and now I try to push my data to the new one. Client: Windows, TortoiseGit Server: docker git-server The log when trying to push git.exe push --progress "...
0
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2answers
387 views

Can TCP Keepalive technique be used to prevent DDOS?

I am learning about DDOS and the techniques to mitigate it. TCP Keepalive is used to check if the other host is still up and if the host does not acknowledge the tcp keep alive message, the connection ...
0
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1answer
1k views

Apache2,4 + Prefork + Keep-alive On

I'm trying to speed up a website with a lot of images that are served from a separate subdomain static.example.com (same IP as www.) Using the pingdom tool noticed that first 5-6 requests (on static....
0
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2answers
1k views

how to emulate a browser that doesn't have “Keep alive”

I have a remote webserver listening on port 80, which serves a page which loads 100 individual .png files (from the same server and hostname) via 100 <img /> tags. On that remote server I do ...
1
vote
1answer
857 views

Amazon ELB doesn't clean up KeepAlive connections

AWS documentation mentions the following: To ensure that the load balancer is responsible for closing the connections to your instance, make sure that the value you set for the HTTP keep-alive ...
0
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0answers
426 views

How to make nginx mail auth connection persistent?

We are using nginx 1.7.3 as a reverse proxy for our Mail SMTP service. For authentication of each SMTP connection, we have configured nginx to connect with a http based service for authentication. ...
1
vote
1answer
249 views

Apache on Windows occupied by Chrome keep-alive

Chromes keep-alive packets seem to block Apache from answering all requests from other clients. They do not appear in the access log nor in mod_status and the browsers keep waiting for an answer. This ...
0
votes
1answer
79 views

Apache delays serving an empty html file while processing a concurrent request

I have a website, which queries a Varnish server, which queries an Apache server, which queries a db server. At 07:00:00, a request is send to the Apache server, which triggers a db request that ...
1
vote
2answers
854 views

jenkins cli build via ssh is disconecting after 10 minutes

I have two jenkins instances. I want job at 1st instance to invoke job at 2nd instance, wait until it ends and perform some actions (using artifacts produced by job @ 2nd) I've come up with this ...
2
votes
1answer
3k views

Why can't Nginx reuse connection to upstream while serving sequential requests from clients?

As mentioned in http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive It should be particularly noted that the keepalive directive does not limit the total number of connections to ...
0
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0answers
389 views

Unable to get Nginx/Apache + FastCGI + PHP-FPM + HTTP/1.0 to use Keep-Alive

For a reason beyond my control (an app that cannot be modified), I need to get a server that processes HTTP requests for PHP pages over FastCGI, to honour "Connection: Keep-alive" (sent by said client)...
1
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0answers
420 views

socket_keepalive configuration for mod_jk

I have Apache httpd with mod_jk. I have issue with killed connections after long idling period: Apache stops to respond and each HTTP request hangs for 15 minutes. I tried turn off mod_jk connection ...
2
votes
1answer
653 views

Linux GRE keep alive

What are possibilities in Linux kernel (?) to work with Cisco endpoint encorporating GRE keep-alives? We have GRE IPsec tunnel set up with another company. We would like to have backup tunnel which ...
2
votes
2answers
2k views

KeepAlive in Apache 2.4 interfering with form submissions

I have just upgraded a server to Debian Jessie, which includes Apache 2.4.10 (was 2.2), and PHP 5.6. Now, SSL sites won't submit forms in some circumstances on IE11 and iPad Safari (not sure about ...
1
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2answers
2k views

Keeping TCP connections alive to track which clients are online

I am developing an application where a server needs to stay in touch with lots of simple IoT devices. Nearly no information exchange is needed between the server and each device, but devices need to ...
0
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1answer
622 views

TCP Keepalive: Why does an idled ESTABLISHED connection end after 60 seconds, instead of tcp_keepalive_time?

I am investigating ways to mitigate a server against DoS-type attacks. In one scenario, I've opened several hundred TCP connections to my webserver. I do not send any data after the initial TCP ...
0
votes
1answer
53 views

WebSphere breaks connection while servlet continues to work

We have an application running on WebSphere. Requests are often running for a long time (tens of minutes). Our users report that Internet Explorer breaks connection and shows blank screen after some ...
1
vote
1answer
838 views

Keepalived + Haproxy performance, apache or nginx? [duplicate]

I have a question about Keepalived + Haproxy. At work I am assigned to deploy a redundant web server with Keepalived and Haproxy. Our setup at the moment is as follows: Apache (as load balancer) + ...
6
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2answers
1k views

(Why) does FreeBSD 'net.inet.tcp.always_keepalive' violate RFC1122?

While working on a server application that runs on FreeBSD and uses TCP, I noticed that TCP keepalive probes get sent even though my application explicitly disables SO_KEEPALIVE on TCP sockets. ...
1
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0answers
7k views

HAProxy resetting backend connections

I'm in the process of setting up a series of servers as proxies to our application server, primarily to obscure the application server's IP as part of a suite of anti-DDOS measures. My goal is to ...
2
votes
0answers
1k views

Keepalive best practices for Nginx-Haproxy-Apache chain

I am using Nginx to serve static content, and Haproxy to proxy requests to multiple Apache2 backends discovered via Zookeeper. Nginx -> Haproxy -> Apache2 According to the official Nginx website, it ...
3
votes
1answer
2k views

How does apache handles connections and requests using worker and prefork mpm modules?

I know that prefork module in apache creates one master process and several child processes to handle connections, my question is: Does each prefork child handles one connection or handles one ...
0
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1answer
1k views

Configure Server to Initiate Http Keep-Alive

I have a set of clients that aren't including an http keep-alive header in their requests to my server. If I use something like Varnish to filter the incoming requests and add the keep-alive header ...
6
votes
1answer
22k views

Haproxy - timeout http-request vs timeout http-keep-alive vs timeout server

I'm trying to wrap my head around how the haproxy options timeout http-request <timeout> timeout http-keep-alive <timeout> timeout server <timeout> interact with each other. I'm ...
-2
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1answer
725 views

HTTP connection keepalive logic [closed]

I am fairly new to HTTP and pardon me if the question looks stupid. I cant get my head around the HTTP keepalive logic. I am studying HTTP definitive guide. We send multiple requests , response over ...
3
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1answer
5k views

Relationship between tcp state TIME_WAIT & HTTP keep-alive

What is the relationship between keep-alive on a HTTP request and a tcp socket in TIME_WAIT - should they be correlated? Furthermore, should system and web server settings be aligned e.g. server.max-...
1
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0answers
670 views

How to force/fake linux eth0 in 'up' status even without cable connected?

One of my testing script is eth0 status related, when eth0 goes down(cable unplugged), the script exit, and i need to unplug and plug cable many times due to test needs. is there anyway can fake ...
3
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1answer
2k views

Tuning Apache KeepAlive Timeout for HTTPS

My website forces HTTPS everywhere and has an average first load time of 3-5 seconds. Thanks to caching, repeat load time is 0.8 seconds. The SSL negotiation takes 150-300ms on my server, so I want ...
19
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3answers
31k views

nginx connection timeout & client closed connection issue

I have this nginx server running on AWS & it was working all fine until recently when couple of users started complaining about the website not opening until they made some 10 attempts to access ...
2
votes
1answer
7k views

option http-server-close on HAProxy haproxy-1.5-dev19 will result in Connection: close header sent in response

I basically have the following issue: whenever I add option http-server-close to the haproxy config (either in frontend or backend section), haproxy will send a Connection: close header in the ...
0
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3answers
2k views

Which settings schould be changed to lower apache CPU usage and use more RAM?

On our CentOS 6 server, we have now a lot of CPU overload, while our RAM is almost not used. KeepAlive is set to "on" because we have some AJAX elements on your website and serving many files such as ...
5
votes
2answers
2k views

Apache: Force HTTP 1.1 or Persistent/KeepAlive connections for HTTP 1.0 requests

I want to force Keep Alive or Persistent connections for all HTTP requests on my Apache 2.2.3 server running on RHEL 5.8. A lot of web crawlers are using HTTP 1.0 for some reason, and I would like to ...
1
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0answers
274 views

tcpdump expression to show zero-byte ACKs?

I want to show zero-byte TCP keepalives sent and received. While this could be generally useful, in this particular case I want to prove that a change I made to the JDBC driver (adding tcpKeepAlive=...
12
votes
1answer
21k views

Should `keepalive_timeout` be removed from Nginx config?

Which is the better configuration/optimization: to explicitly limit the keepalive_timeout or to allow Nginx to kill keepalive connections on its own? I have seen two conflicting recommendations ...
0
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2answers
2k views

Http Persistent Connection (keep-alive) and port numbers

Is a persistent http connection (keep-alive), always bound to a specific port, or can it use a range of ports?
0
votes
1answer
534 views

How do I know that my TCP connection is safe from the Firewalls/NAT?

Being on the Azure cloud, I found that the firewalls there drop connections between the Web server and the database quite often. Mostly when there was some inactivity, I think something between 5 and ...
0
votes
1answer
2k views

How do I change my ubuntu keepalive to infinity?

http://www.golinuxhub.com/2013/03/setting-up-custom-tcpip-keep-alive.html Once I connect to my development server, I don't want it to automatically disconnect unless I quit my terminal. What ...
0
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0answers
504 views

Scriptable FTPS client able to send Keep Alive to control port?

We need a FTP client that satisfies the following constraints: Windows Command-line scriptable, so we can automate it...sorry, FileZilla (?) FTPS, as it seems to perform better than SFTP The ability ...
4
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2answers
5k views

Large keepalive_requests values are severely slowing-down Nginx

When running a bacon (43-byte transparent pixel) load test on Nginx, we have tried several keepalive_requests values (from 10 to 100,000) and the optimal value seems to be 10. Here are the server ...
1
vote
1answer
1k views

Do keepalives to socket connections exist?

Pre briefing: Although my question is broad on purpose, I am dealing with nginx connecting to php-fpm (fcgi), which is served via a local socket (/tmp/somesocket.socket). Nginx has a setting to ...
0
votes
1answer
767 views

Making Dovecot keep its TCP connections alive?

I'm trying to run a benchmarking application which connects to my IMAP server and has a "warm up" phase during which IMAP connections are being established. I've set my limits properly and the mail ...
4
votes
2answers
3k views

Trying to understand how keep-alive works

Today we encountered a problem on the server, when files/scripts took more that 3 seconds to load. The solution was simple - just increasing MaxClients to the estimated memory limit. But I am worried ...
1
vote
1answer
825 views

Is tcp_keepalive application dependant on Linux?

According to http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/index.html , the kernel keepalive function occurs at the OS level, and doesn't require an application to explicitly call it. However I also read ...