System information

6.4 Monitoring Software
00000e0 027 027 P 027 C 027 I 027 P 027 n 027 P 027
00000f0 027 027 027 027 P 027 o 027 w 027 e 027
0000100 r 027 027 027 027 027 B 027 o 027 o 027
0000110 t 027 027 027 027 027 S 027 e 027 c 027
0000120 u 027 r 027 i 027 t 027 y 027 027 027 027
0000130 027 E 027 x 027 i 027 t 027 027 027 027
As shown above, the address "00000a0" contains the entry of the "Main" menu item.
The corresponding attributes have the value "161", which defines a blue letter and a white
background. In contrast, the other menu items like "Advanced" have an attribute byte with
the value "027" - white letters on a blue background.
But the detection of highlighted text can also be possible running a graphical video mode.
Video modes using four video planes separate the pixel information into three color bits and
one intensity bit, whereas every bit is related to a dedicated video plane. Thus, the OCR of
the video plane storing the intensity bits returns the highlighted text of the screen content.
6.4 Monitoring Software
The CHARM card has a couple of sensors to inspect the host computer. Every sensor has
its own program to setup the related hardware or to print out the measured value, e.g. the
program hostTemperature is used to get the data of the temperature sensors. Monitoring
software like Nagios [84] or Lemon [85] provide a global view of a range of sensor information.
Furthermore, the monitoring software informs the administrator about sensor information
which exceed a certain threshold. Pending errors can be recognized and the administrator
can take an appropriated action at an early stage. Two monitoring clients run on the
CHARM: a Lemon client and a SysMES client. Both client and framework are explained
in the following section.
Lemon Interface
The HLT at CERN uses up to 100 CHARM cards inspecting the cluster nodes [33]. As
described in section 6.2.3, the CHARM card provides a couple of sensor data per node:
temperature, voltage, POST codes and fan speed values. The HLT uses the monitoring
framework LHC Era Monitoring (Lemon) to monitor the sensor data of each the node of
the cluster [85]. Lemon is a server/client based monitoring system. A Lemon client is
running on the CHARM cards at the HLT which sends the sensor data to a central Lemon
server. In this case, the client has been adapted to run on each CHARM card at the
HLT. The server stores the data to a database and finally a web application provides the
collected sensor values. Figure 6.11 shows a screen-shot of the Lemon web front-end of the
HLT cluster.
SysMES Interface
The SysMES framework [86] is a scalable, decentralized, fault tolerant, dynamic, rule based
tool set for the monitoring of networks of target systems. SysMES is an acronym for
89