Connection reset by tomcat server on continuous reception of HTTP GET request - server

I am doing load test of web server. Current i am using tomcat 6 to test my code. While running the server resets the connection after few minutes on receiving continuous GET requests for the same page. If I send GET request with some gap (say 500 ms) then it works fine. If I send GET request with 10 ms or less than 10 ms then server resets the connection after few seconds from the start of test. Please help on how to fix this problem. What is the reason for reset ? Whether the server is overloaded or I have to perform some operation while establish connection ??.
My GET request format is:
GET /index.html HTTP/1.1
Host: 180.168.40.40
Connection: keep-alive

Related

REST client gives error, while HTTP looks fine

My interface (an MKR Wifi 1010 Arduino) runs a very simple REST API, but when testing it with Mulesoft's Advanced Rest Client, I get this error:
The requested URL can't be reached
The service might be temporarily down or it may have moved permanently to a new web address.
The response status "0" is not allowed. See HTTP spec for more details: https://tools.ietf.org/html/rfc2616#section-6.1.1
When I check it with telnet though, it looks fine:
[bf#localhost ~]$ telnet 192.168.178.185 80
Trying 192.168.178.185...
Connected to 192.168.178.185.
Escape character is '^]'.
GET /api/gps HTTP/1.1
Host: 192.168.178.185
HTTP/1.1 200 OK
Connection: close
Content-Length: 9
Content-Type: application/json
"Success"
Connection closed by foreign host.
My question now is, is the rest client broken, or am I missing something in my reply? Of course I want any REST client to be able to process my interface correctly.

haproxy - layer 7 health check failure

I am getting occasional layer 7 health check failures. This happens on production machine seemingly at random, maybe once a minute or every few minutes on average. Here is the configuration:
backend api
mode http
option httpchk GET /api/v1/status HTTP/1.0
http-check expect status 200
balance roundrobin
server api1 127.0.0.1:8001 check fall 3 rise 2
server api2 127.0.0.1:8002 check fall 3 rise 2
The HAproxy log tells me the following:
Health check for server api/api2 failed, reason: Layer7 timeout, check duration: 10001ms, status: 2/3 UP.
Strange thing is when I run a script to fetch the same URL at a much faster pace than HAproxy, it never fails to return 200 response. It never hangs like it seems to do for HAproxy.
In addition, I'm getting occasional HAProxy error for various API calls, not just health checks, all looking quite similar:
https-in~ api/api1 45/0/0/-1/30045 504 194 - - sHVN 50/49/13/10/0 0/0 "POST /api/v1/accounts HTTP/1.1"
What could be the issue here? This one really got me stumped.

Telit 4G modem LE920-EUG, giving error on http commands, AT#HTTPCFG.. AT#HTTPQRY any http command not working

I have the Telit LE920-EUG 4G LTE module. I am trying to execute GET and POST http requests to a remote server. Though the PDP context is activating properly and I have internet access on the SIM that I'm using, I can't seem to be able to connect to a remote server and execute HTTP requests (both POST and GET) from the module.
I have tried two ways, one through direct HTTP commands supported by the module(All commands mentioned in the LE9x0 AT command reference guide), the commands sequence for which is mentioned below, but +CME ERROR: 100 occurs, and it's same for every http command(AT#HHTPQRY, AT#HTTPRCV) that I try to execute.
AT#SGACT=1,1
#SGACT: 31.81.208.1
OK
AT#HTTPCFG=0,"httpbin.org",80,0,,,0,120,1
+CME ERROR: 100
//No configuration details
AT#HTTPCFG?
+CME ERROR: 100
AT#HTTPCFG=?
+CME ERROR: 100
I have also tried the GET and POST commands after socket dialing. The socket connects but they are not receiving any data from the server or posting anything onto the server, the connection closes with a NO CARRIER. The command sequence that I'm using is given below
//Socket Dial
AT#SD=1,0,80,www.m2msupport.net
CONNECT
//GET commands sequence
GET /m2msupport/http_get_test.php HTTP/1.1
Host:www.m2msupport.net
Connection:keep-alive
//Connection closes with No Response
NO CARRIER
//Socket info shows the bytes sent
at#si=1
#SI: 1,86,0,0,0
OK

Wget gives up too quickly on a Express API

I want to download the result of a Express.js REST API which is very slow to process (~10 minutes). I tried few timeout options with wget but it gives up after few minutes while I ask it to wait around ~60 000 years.
wget "http://localhost:5000/slowstuff" --http-user=user --http-password=password --read-timeout=1808080878708 --tries=1
--2015-02-26 11:14:21-- http://localhost:5000/slowstuff
Resolving localhost (localhost)... ::1, 127.0.0.1
Connecting to localhost (localhost)|::1|:5000... connected.
HTTP request sent, awaiting response... 401 Unauthorized
Authentication selected: Basic realm="Authorization Required"
Reusing existing connection to [localhost]:5000.
HTTP request sent, awaiting response... No data received.
Giving up.
EDIT:
The problem doesn't come from the wget timeout value. With a timeout set to 4 seconds, the error is different: Read error (Connection timed out) in headers. And I have exactly the same problem with curl.
I think the problem comes from my API. It looks like a timeout of 2 minutes is set by default in NodeJS.
Now, I need to find how to change this value.
This
--http-password=password--read-timeout=1808080878708
is missing a blank. Use
--http-password=password --read-timeout=1808080878708

PostgreSQL frontend unexpectedly closes connection

I'm a little bit confused with the following case.
I've got a Postgres server running on host A, and a java based client running on host B. The client uses org.postgresql.Driver JDBC driver (version 9.1-901.jdbc3).
sometimes while executing long running stored procedure I get exception "java.net.SocketException: Socket closed". I'm using org.apache.commons.dbcp.BasicDataSource for retrieving
connections.
DBCP pool is configured with default options.
I got tcp dump in order to figure out on which side (client or server) socket is being closed;
Here is what I've got:
1. Client B sends a test query message when tries to borrow connection from dbcp pool ("Select 1")
2. Server A sends successful response back (Type: Command completion, Ready for query)
3. Client B sends ACK message in response on server A response (see the item 2).
4. Client B sends query message to the server A.
5. Server A sends ACK message in response on client Query message (see the item 4).
6. Client B sends terminating message (Type : Termination) after some time passed (from 3 to 10 or sometimes even more minutes).
7 Client B sends FIN ACK message to the server.
8. Server A sends back ACK on termination message.
9. Server A sends ACK on (FIN, ACK) message (item 7).
10. Server A sends back a response on the client query (from item 4) Type: Row description Columns: 40.
11. Client B sends RST message (reset).
12. Server A continues sending response on the query Type: Data row Length: 438 Columns 40 and so on.
13 Client B sends RST message (reset) again.
14. Server A continues sending response on the query Type: Data row Length: 438 Columns 40 and so on.
15. Client B sends RST message (reset).
After that communication seems to be finished.
After the item 6, in my client logs I got Exception like the following:
Caused by: java.net.SocketException: Socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:152)
at java.net.SocketInputStream.read(SocketInputStream.java:122)
at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:145)
at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:114)
at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:73)
at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:274)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1661)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
Could you please help me to figure out the reason of such a failure. (This bug happens once per 10 successful cases.)
We had a similar problem, and it was caused by a firewall or connection tracking router between the server and the client.
I am guessing you took the tcpdump on the server side. The query runs for a considerable time with no traffic on the connection. The firewall has a timer on the open connection; it expires and the firewall closes the connection towards the server, and also back towards the client. On the capture at the server side, it looks like the client is closing the connection.
You could verify this by capturing on the client side simultaneously as you capture on the server side - on the client side it will look like the server has closed the connection, while on the server side it looks like the server is closing the connection. In reality the firewall is closing it in both directions.
To prevent this, you can set tcp_keepalives_idle, tcp_keepalives_interval and/or tcp_keepalives_count (if your OS supports TCP Keepalives). Alternatively, you will have to change the settings on the firewall.