Download Chapter 1 Introduction to EverBEEN

CHAPTER 2. EVERBEEN USER GUIDE
18
• Each run of EverBEEN creates separate working directory for its tasks in the tasks subdirectory
(2).
• On restart a new working directory for tasks (3,4,5,6) is created. Names of these directories are
based on the node startup (wall clock) time. EverBEEN on each start checks these directories and if
their number exceeds 4 (by default), the oldest one is deleted. This prevents an unexpected growth
of the Host Runtime working directory size, but allows debugging failed tasks when the underlying
Host Runtime is terminated and restarted. The number of backed up directories is configurable by
the hostruntime.tasks.wrkdir.maxHistory configuration option.
• Working directories of tasks (7,15,16,17) contain files from an extracted BPK (8,9,10,13,14) and log
files for the standard error output (11) and standard output (12).
The working directory of a task is deleted only if the task finished its execution without error, otherwise
the directory remains unchanged. Alternatively, you can either clean up the directory manually or use
the Web Interface for that purpose.
2.3.3
Limitations
• If you want to run more than one Host Runtime on the same machine we strongly recommend to
start each node with a different working directory name. Running multiple instances concurrently
with the same working directory is not supported.
• Running EverBEEN for a long time without clearing directories after failed tasks can result in low
disk space.
2.4
Web Interface
The Web Interface is the tool to interact with the EverBEEN framework.
2.4.1
Connecting to the cluster
First, the Web Interface needs to connect to the EverBEEN cluster (Figure 2.1 ). You have to provide
cluster connection credentials. If you run your nodes with default configuration, default host name, port
(type of the node must be DATA), group name and group password is prefilled in the login form. Click
on connect to establish a connection with the cluster.
Figure 2.1: Login
2.4.2
Cluster overview
The overview page (Figure 2.2 ) shows a quick overview of connected nodes, node resources, currently
active or failed tasks and task logs.