Here is another example of how I see this uber script helping with maintenance and
support. The user gets an alert notification that warns about high read latencies on the
twenty_four_metrics table. The notification suggest that the user runs,
$ rhq.sh row-cache --enabled --table twenty_four_hour_metrics
On Mar 12, 2013, at 9:18 AM, John Sanda <jsanda(a)redhat.com> wrote:
A little more background on my thinking so far may be helpful. I do
not see this as being simply a start/stop script since its purpose will be to encapsulate
functionality provided by server, agent, and Cassandra scripts. I see the script providing
functionality making it easier for users to administer Cassandra as well as for providing
support. Here is an example to help illustrate. Disk space is filling on the machine due
to metrics storage. The solution might be for the user to run,
$ rhq compact
which will merge all of the data files on disk, reducing overall disk usage. Now to the
questions.
Q: If I launch rhq-uber, how many processes are started?
Assuming a default install, 3 processes would be started, server, agent, and cassandra.
Q: If I kill that script what happens to those processes?
Since the script will be starting multiple processes, I am not sure running in the
foreground will work. That is something to be investigated. If we can make it work, then I
would expect to kill each of the processes that it starts. If running in the foreground
does not work, then the user would have to use a shutdown command, rhq shutdown, which
would kill each of the processes.
Q: I assume that the script will offer the same functionality as the existing one - how
does the 'console' option work?
Running rhq-server.sh console keeps the process in the foreground and writes log
statements to stdout. Starting Cassandra with cassandra -f does the same thing. While the
agent console runs in the foreground it is different since it is interactive. I have
thought of a couple options so far.
1) The console command takes an argument whose value is one of server, agent, or
Cassandra. Only the specified process is started in console mode.
2) The console command takes an argument same as before. The process specified by the
argument is started in console mode, and the others are started in the background.
On Mar 12, 2013, at 8:39 AM, Alan Santos <asantos(a)redhat.com> wrote:
> Hi John - I think this is the right direction.
>
> A few questions -
>
> If I launch rhq-uber, how many processes are started?
>
> If I kill that script what happens to those processes?
>
> I assume that the script will offer the same functionality as the existing one - how
does the 'console' option work?
>
>
> thanks
>
>
> On Mar 11, 2013, at 5:49 PM, John Sanda <jsanda(a)redhat.com> wrote:
>
>> There has been a lot of discussion recently around how RHQ and Cassandra should
co-exist. The decision has been made to proceed with the following,
>>
>> * Installing RHQ server will also install Cassandra and agent by default.
>> * Advanced options will be available to install RHQ server by itself or just
Cassandra and agent.
>> * Managing/monitoring Cassandra will be done via the agent.
>> * Starting/stopping the server will by default start/stop everything that is
installed on the machine.
>>
>> Rather than changing existing scripts like rhq-server.sh to provide this
augmented functionality, what do you think about an rhq-uber script (e.g., rhq.sh) that
handles these changes? If I execute,
>>
>> $ rhq.sh start
>>
>> The the script will start Cassandra, the server, and the agent, assuming a
default installation. The nice thing about this is that if the user only wants to
start/stop the server, he can instead directly use the already familiar rhq-server.sh
script; however the uber script would also provide that capability as well. Maybe
something like,
>>
>> $ rhq.sh start --server-only
>>
>>
>> The new script would provide for centralized command and control of everything
installed on the box.
>>
>>
>> - John
>> _______________________________________________
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>>
https://lists.fedorahosted.org/mailman/listinfo/rhq-devel
>
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