Install samba and krb from yum, then run the following… authconfig –disablecache \ –enablewinbind \ –enablewinbindauth \ –smbsecurity=ads \ –smbworkgroup=howard.local \ –smbrealm=HOWARD.LOCAL \ –enablewinbindusedefaultdomain \ –winbindtemplatehomedir=/home/%U \ –winbindtemplateshell=/bin/bash \ –enablekrb5 \ –krb5realm=HOWARD.LOCAL \ –enablekrb5kdcdns \ –enablekrb5realmdns \ –enablelocauthorize \ –enablemkhomedir…
Category: Linux
Determining the order of java classes called
I thought this was pretty interesting, and perhaps incredibly useful. While attempting to understand the call stack (and being too lazy to read through reams of source code), I found that calling a java class will result in stat() system…
Wrong permissions on /tmp cause havoc with java
We had a server that had been behaving oddly since at least April. I finally discovered why. jps returns nothing, which is the first symptom. When we strace, we see it can’t write to /tmp (our setting for java.io.tmpdir), so…
Does java reuse closed sockets when the host still has one open?
We were curious as to what the handoff is between an application that opens a network socket, and how the Linux OS handles it. Let’s assume we do what is below: import java.net.*; public class checkSocket { public static void…
net.ipv4.ip_no_pmtu_disc and don’t fragment
We received an email asking that we restart a given server as the ATG lock manager had a required lock and a scheduled job could not move forward. I don’t like to do that without some triage. We were stuck…
Where is a given thread connecting?
We start by getting the PID of our running JVM… -bash-4.1$ jps 29527 Main 3560 Jps …then we print each lightweight process (threads in our JVM) in which we are interested. In our case, these are threads with zafu in…
Installing a specific kernel related package without upgrading the kernel
If you simply type “yum install package_name”, you will get the most recent version available in the package repository to which you are pointing. If this is a kernel related package, you can inadvertently upgrade the kernel, which may be…
Which threads are talking to the database?
Often while troubleshooting, I will want to know where the bottleneck is. If I think the database may be the culprit, I will run the following to print those threads that are making database calls… -bash-4.1$ jstack 20711 | awk…
Determining the source of high java CPU
This post is related to a situtation in which you find yourself with high CPU utilization, but can’t determine the source. This will gather thread dumps and the CPU used by each thread. For the threads that use a large…
Which threads are running on a given CPU
We had a need to see which threads were running on a given CPU, as utilization was not balanced amongst the cores. We used what is below to do so. In our case, our java PID was 488. -bash-4.1$ jstack…