| 9 |
|
|
| 10 |
|
CORE |
| 11 |
|
---- |
| 12 |
+ |
The core of the system provides little or no functionality |
| 13 |
+ |
to the operation of the system, but instead oversees the |
| 14 |
+ |
running. At startup this should be the first component to |
| 15 |
+ |
intansiate. It essentially acts as a central logging and |
| 16 |
+ |
configuration distrubution site, the "central" in |
| 17 |
+ |
centralised monitoring system. It may also be running the |
| 18 |
+ |
ORB or some components related to it. |
| 19 |
|
|
| 20 |
+ |
On startup the first thing it should do is read in any |
| 21 |
+ |
configuration files, start the logging interface then |
| 22 |
+ |
prepare to bring the system online. This is done by |
| 23 |
+ |
starting the various components. If however the system |
| 24 |
+ |
configuration states that particular components are |
| 25 |
+ |
operating in "distributed" mode, then it blocks until |
| 26 |
+ |
the various key components have registered that they are |
| 27 |
+ |
online. |
| 28 |
|
|
| 29 |
|
Client Interface |
| 30 |
|
---------------- |
| 31 |
+ |
The Client Interface is essentially just one component with |
| 32 |
+ |
a series of lists within it. When run it should, obviously, |
| 33 |
+ |
create an instance of the Client Interface, and then bind |
| 34 |
+ |
this to the ORB and register with the naming service. |
| 35 |
|
|
| 36 |
+ |
It can then read its configuration in from the CORE and get |
| 37 |
+ |
a hook on the logging service that the CORE provides. |
| 38 |
|
|
| 39 |
+ |
It then needs to construct the "local clients". These |
| 40 |
+ |
clients communicate with the system using the same interface |
| 41 |
+ |
as the external clients, but they are tailored to specific |
| 42 |
+ |
purposes, such as E-Mail alerts, and SMS alerts. The Client |
| 43 |
+ |
Interface then listens on a "well known" address for clients |
| 44 |
+ |
to request a connection. |
| 45 |
+ |
|
| 46 |
|
Filter |
| 47 |
|
------ |
| 48 |
|
The filter is broken down into three main subcomponents. |
| 70 |
|
At startup a Filter Manager object is activated at the "well |
| 71 |
|
known" location (probably a given machine name at a |
| 72 |
|
predefined port). The Filter Manager will create an instance |
| 73 |
< |
of the Main Filter, and any Filters under it's control. |
| 74 |
< |
Through some mechanism the other Filters, elsewhere on the |
| 75 |
< |
network, will register with the Filter Manager. The |
| 48 |
< |
Filter Manager will need to tell each Filter the location |
| 49 |
< |
of the Main Filter upon registering. The Filter Manager will |
| 50 |
< |
then be in a position to receive connections from hosts and |
| 51 |
< |
pass them off to Filters. |
| 73 |
> |
of the Main Filter, and any Filters under it's control. It |
| 74 |
> |
should also bind itself to the ORB and register with the |
| 75 |
> |
naming service. |
| 76 |
|
|
| 77 |
+ |
It can then read its configuration in from the CORE and get |
| 78 |
+ |
a hook on the logging service that the CORE provides. |
| 79 |
+ |
|
| 80 |
+ |
Through some mechanism the other Filters, elsewhere on the |
| 81 |
+ |
network, will register with the Filter Manager. The Filter |
| 82 |
+ |
Manager will need to tell each Filter the location of the |
| 83 |
+ |
Main Filter upon registering. The Filter Manager will then |
| 84 |
+ |
be in a position to receive connections from hosts and pass |
| 85 |
+ |
them off to Filters. |
| 86 |
+ |
|
| 87 |
|
System Running State |
| 88 |
|
******************** |
| 89 |
|
|
| 90 |
|
CORE |
| 91 |
|
---- |
| 92 |
+ |
Once the various components are running then the core is |
| 93 |
+ |
essentially idle, logging information and handling |
| 94 |
+ |
configuration changes. |
| 95 |
|
|
| 59 |
– |
|
| 96 |
|
Client Interface |
| 97 |
|
---------------- |
| 98 |
+ |
In the running state the Client Interface is always |
| 99 |
+ |
listening for clients on the "well known" address. When a |
| 100 |
+ |
connection is received it is passed in to the main Client |
| 101 |
+ |
Interface and the client is queried about which hosts it |
| 102 |
+ |
wishes to receive information about. This is then stored in |
| 103 |
+ |
an internal "routing table" so the Client Interface knows |
| 104 |
+ |
which hosts to send the information on to. This routing |
| 105 |
+ |
table is constructed with this form; |
| 106 |
|
|
| 107 |
+ |
host1: client1 client2 client5 |
| 108 |
+ |
host2: client2 |
| 109 |
+ |
host3: client3 client4 |
| 110 |
+ |
host4: client1 client3 |
| 111 |
+ |
|
| 112 |
+ |
This design is such that when a piece of information is |
| 113 |
+ |
recieved from a host the Client Interface can immediately |
| 114 |
+ |
see which clients wish to receive this data, without too |
| 115 |
+ |
much searching. |
| 116 |
+ |
|
| 117 |
+ |
The "local clients" function just like any other client, |
| 118 |
+ |
although they are local, in that they will wish to receive |
| 119 |
+ |
information about hosts they are interested in. However, |
| 120 |
+ |
they will contain a lot more logic, and be required to work |
| 121 |
+ |
out who wants to be alerted about what, and when. They will |
| 122 |
+ |
also be responsible for sending the alert. |
| 123 |
|
|
| 124 |
|
Filter |
| 125 |
|
------ |
