If you see those errors in your mail.log and your emails are failing to send, you need to add your ssl cert from apache to the sendmail config in /etc/mail/sendmail.cf:
I was getting the following error when I tried testing with openssl: error:140790E5:SSL routines:SSL23_WRITE:ssl handshake failure:s23_lib.c:177 The solution? It turns out that /etc/default/slapd needs to be configured to use /etc/ldap/ldap.conf using the following:
The thing I spent the longest on was getting supervisor to work. Gunicorn kept giving me "gunicorn.errors.HaltServer: <HaltServer 'Worker failed to boot.' 3>", because I was missing the "directory" parameter. I needed to tell supervisor which directory to start from.
I have a flask application running on Ubuntu which reads from a file and creates several large dictionaries. After the dictionaries are created and flask returns the request, the memory used for the dictionaries is not released back to the OS. This example shows the problem: https://gist.github.com/pawl/c3ed7663b94abec01d75
I dug even deeper and learned this is a Linux thing: "Python returns memory to the OS on the heap (that allocates other objects than small objects) only on Windows, if you run on Linux, you can only see the total memory used by your program increase." http://deeplearning.net/software/theano/tutorial/python-memory-management.html
"We compiled a version of Python with TCMalloc that only uses mmap. When testing the new Python in one of our largest projects, we found that not only did Python give back memory to the OS correctly, it also had a reduced memory usage and no apparent CPU penalty for using mmap instead of brk." - http://pushingtheweb.com/2010/06/python-and-tcmalloc/