Re: [Server-devel] Server performance feedback and testing suggestions
On Sun, Aug 1, 2010 at 6:20 PM, David Leeming wrote: > OK, well we have set it up to run 24/7 with the timer override, allowing > teachers to set the timer to auto if need be (but then they will have the > daily task of manually switching it on, that can get neglected in my > experience, especially as the servers are in locked rooms, with the daily > hassle of finding keys etc. Sounds a minor issue but in practice it is best > to have the system as automated as possible). As Tabitha (Tom?) mentions, some of these machines have a setting in the BIOS that will auto-switch-on whenever it has electrical power. Worth a try. > We also added a line to the cron table (crontab -e) to have a daily reboot > just because we have been brought up to think that is a good thing!!! Two strong recommendations: - Daily flossing good, daily reboots bad ;-) - Don't use crontab -e! Write a file in /etc/cron.d/ -- much better! You need to add the user it runs as, like */5 * * * * root /my/command > We reconfigured with smaller groups (less than 35 per group) and it tested > OK - 6 class groups all independently collaborating and isolated from each > other. Ok. That makes me feel much better. How large were the groups before? cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
Re: [Server-devel] Server performance feedback and testing suggestions
On 01/08/2010, David Leeming wrote: > OK, well we have set it up to run 24/7 with the timer override, allowing > teachers to set the timer to auto if need be (but then they will have the > daily task of manually switching it on, that can get neglected in my > experience, especially as the servers are in locked rooms, with the daily > hassle of finding keys etc. Sounds a minor issue but in practice it is best > to have the system as automated as possible). There should be an option in the bios to turn on when power is applied. Our Samoan EEEBoxes have "off", "on"and "last state" (where it turns on if it was on when power was lost). Then you can use your timer to automatically turn it on. -- Kind regards Tabitha Roder (actually it's Tom here) ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
Re: [Server-devel] Server performance feedback and testing suggestions
Some feedback inserted David, quick comments as you have short time over there. On Fri, Jul 30, 2010 at 5:31 PM, David Leeming wrote: > - One "eBox" fanless VIA server with 1GB RAM (non-expandable). We had > planned two (one for G3-4 and one for G5+) but vital eqt did not show up in > time so we are managing with one. One server should be ok > - Campus wide wireless network, solar powered, using a ratio of less than > 30 XOs per AP. >>Super! > Layout is 3 x single storey double classrooms (G3A, 3B... 4A, 4B...etc) in > line, separated by about 15m. The server is situated in a parallel line of > classrooms about 6m to one side. We use some centrally located solar power > supplies with POE. The whole system is DC powered and we use digital; timers > to turn things off when not needed to save power. However the system > provides good access for at least 15 hrs per day. >>Great idea on the digital timers -- when you have a chance, documenting the setup would benefit other deployments. Will be posting up details on wiki pages when I get a chance. But we are using Sundaya S4 kist with the 55W panels doubled up with 2A loads or less. The units are self contained, well priced, and the system is modular so that if one part goes down due to low voltage it doesn't pull the rest. So far we have seen the unit with the server (1.5A load) running all night reaching full charge by 11am even on a cloudy day. The 12V DC digital timers were sourced from Rainbow Power, www.rpc.com.au) > (Advice on power management): I would like suggestions how the server can be > safely turned on and off automatically. >>I have designed the server so that it survives sanely hard power off. >> During development and testing I almost never issue a formal shutdown. >> Removing the powercord is de rigueur. >>Just don't do it during yum / rpm updates (how I wish those were saner!) >>OTOH, given that you have set timers, if everything is running smooth >>you know what time power will be off, so you can set a cronjob at a >>regular time to run shutdown. (As various clocks drift, this won't be >>particularly reliable...) >>Daily reboot _not_ needed. OK, well we have set it up to run 24/7 with the timer override, allowing teachers to set the timer to auto if need be (but then they will have the daily task of manually switching it on, that can get neglected in my experience, especially as the servers are in locked rooms, with the daily hassle of finding keys etc. Sounds a minor issue but in practice it is best to have the system as automated as possible). We also added a line to the cron table (crontab -e) to have a daily reboot just because we have been brought up to think that is a good thing!!! > ... generally the > impression was that networking was functioning well over the entire campus. Excellent! > However, we noticed that collaboration was not working well. XOs could not > see all members of their course in neighbourhood view it seemed to be >>I would have expected that. The ejabberd server (if you've updated the RPMs to the latest from olpcxs-testing) will handle many XOs well, but the neighbourhood view on the XO doesn't cope well with so many XOs. >>The cure: segregate presence by course (see xs techniques and configuration in the wiki for the steps). We reconfigured with smaller groups (less than 35 per group) and it tested OK - 6 class groups all independently collaborating and isolated from each other. As it was the last day and Sunday, we could only do a limited test with 5 XOs per class but we had Chat running with pretty good responsiveness (the icon appearing in a few seconds on all laptops) on each of the 6 classes. Whilst this was happening I measured memory use as 184KB total using ps_mem.py up from 170KB with no XOs active. We'll have to wait for a monitoring visit to get the data on the full load situation. We only had 2 weeks to do all the training and obviously focused on laptop use and classroom integration / the pedagogical side, although one teacher was trained to do basic user management on Moodle. These teachers have mostly NO previous computing experience. > This contrasts with the good responsive and reliable browsing. In this test, > we were using presence service split by course, with the students added as > students and the teachers of those grades added as teachers. No-one was >> Hmmm, so even with segregated presence service you are seeing "slow" presence issues. Can you confirm yum --enablerepo=olpcxs-testing update doesn't bring a new version of ejabberd? Yes was updated. Now works OK (at least based on the reduced load test described above) > given site roles. The teachers were also members of another course > teachers intended to allow collaboration between the teachers in different > grades. > That's best practice -- good. > We would like some feedback on what could be the issue. > Very unlikely to be a problem on your end. An ejabberd bug or ejabberd-moodle interact
Re: [Server-devel] Server performance feedback and testing suggestions
David, quick comments as you have short time over there. On Fri, Jul 30, 2010 at 5:31 PM, David Leeming wrote: > - One "eBox" fanless VIA server with 1GB RAM (non-expandable). We had > planned two (one for G3-4 and one for G5+) but vital eqt did not show up in > time so we are managing with one. One server should be ok > - Campus wide wireless network, solar powered, using a ratio of less than > 30 XOs per AP. Super! > Layout is 3 x single storey double classrooms (G3A, 3B... 4A, 4B...etc) in > line, separated by about 15m. The server is situated in a parallel line of > classrooms about 6m to one side. We use some centrally located solar power > supplies with POE. The whole system is DC powered and we use digital; timers > to turn things off when not needed to save power. However the system > provides good access for at least 15 hrs per day. Great idea on the digital timers -- when you have a chance, documenting the setup would benefit other deployments. > (Advice on power management): I would like suggestions how the server can be > safely turned on and off automatically. I have designed the server so that it survives sanely hard power off. During development and testing I almost never issue a formal shutdown. Removing the powercord is de rigueur. Just don't do it during yum / rpm updates (how I wish those were saner!) OTOH, given that you have set timers, if everything is running smooth you know what time power will be off, so you can set a cronjob at a regular time to run shutdown. (As various clocks drift, this won't be particularly reliable...) Daily reboot _not_ needed. > ... generally the > impression was that networking was functioning well over the entire campus. Excellent! > However, we noticed that collaboration was not working well. XOs could not > see all members of their course in neighbourhood view – it seemed to be I would have expected that. The ejabberd server (if you've updated the RPMs to the latest from olpcxs-testing) will handle many XOs well, but the neighbourhood view on the XO doesn't cope well with so many XOs. The cure: segregate presence by course (see xs techniques and configuration in the wiki for the steps). > This contrasts with the good responsive and reliable browsing. In this test, > we were using presence service split by course, with the students added as > “students” and the teachers of those grades added as “teachers”. No-one was Hmmm, so even with segregated presence service you are seeing "slow" presence issues. Can you confirm yum --enablerepo=olpcxs-testing update doesn't bring a new version of ejabberd? > given site roles. The teachers were also members of another course > “teachers” intended to allow collaboration between the teachers in different > grades. That's best practice -- good. > We would like some feedback on what could be the issue. Very unlikely to be a problem on your end. An ejabberd bug or ejabberd-moodle interaction issue could be what's happening. If you want to make double sure that it's not memory, grab ps_mem.py and run it http://www.pixelbeat.org/scripts/ps_mem.py -- post the results. top (or even better, the output of sar) will confirm that it's not cpu or memory. As for logs, the ejabberd logs are where it's at. And you can ask the ejabberdctl tool a few things when users or shared sessions are not appearing. Can you boil down the problem to a set of steps that repro? cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
[Server-devel] Server performance feedback and testing suggestions
In our PNG deployment we have only just got the system up for testing due to late delivery of most of the infrastructure eqt (we had the laptops so were able to complete the initial training); - 250 XOs divided into six classes G3A - G5B and all 15 teachers - One "eBox" fanless VIA server with 1GB RAM (non-expandable). We had planned two (one for G3-4 and one for G5+) but vital eqt did not show up in time so we are managing with one. - Campus wide wireless network, solar powered, using a ratio of less than 30 XOs per AP. - 1Gb switches used throughout - 1:1 use of 15W thin film (GoldPeak) panels with DC Share cables for the laptops. No power in this school. I have questions about power management for the server, and feedback on server performance. Layout is 3 x single storey double classrooms (G3A, 3B... 4A, 4B...etc) in line, separated by about 15m. The server is situated in a parallel line of classrooms about 6m to one side. We use some centrally located solar power supplies with POE. The whole system is DC powered and we use digital; timers to turn things off when not needed to save power. However the system provides good access for at least 15 hrs per day. (Advice on power management): I would like suggestions how the server can be safely turned on and off automatically. I guess auto off at an agreed time would be easy, turning on might be hardware dependent. Or can we put it into sleep mode when not needed (10pm-7am) and have it running 24/7? With solar power one has to be efficient as possible. If it is run 24/7, we'd like to know how a timed daily reboot can be activated, and whether that is a good idea or just leave it on. (Advice on server performance and testing suggestions): We only have 2 days to test the full system due to the crazy logistical issues that have plagued us. Yesterday we had it all running with the students in the classrooms, logged on to the server OK. They are segregated into 3 courses at the moment (G3, G4, G5) with about 60 students per course. However in the test yesterday it was out of school hours and only maybe 30 students per course (Grade) were present. We observed that browsing the server, both with site files and public folders (such as Schools Wikipedia and the heavier UNESCO ASEAN SchoolNet series of flash animations) was generally working good and the server as responsive. Moodle admin (such as adding users to courses) was working very responsively. So generally the impression was that networking was functioning well over the entire campus. However, we noticed that collaboration was not working well. XOs could not see all members of their course in neighbourhood view - it seemed to be taking a long time to populate the view, and you could see some dropping out occurring - XOs that were on and connected, suddenly disappearing from view on a neighbouring XO. Likewise, sharing activities was almost universally not working - no icon displayed on the course members neighbourhood view. This contrasts with the good responsive and reliable browsing. In this test, we were using presence service split by course, with the students added as "students" and the teachers of those grades added as "teachers". No-one was given site roles. The teachers were also members of another course "teachers" intended to allow collaboration between the teachers in different grades. We would like some feedback on what could be the issue. Is it the low power server with only 1GB RAM? But we only had a maximum of about 90 students divided into the three courses online yesterday. Could it be some inefficiency in the networking? But browsing was working well. Could it be that Moodle is broken in some respect? But during training we were experiencing no issues with collaboration with the teachers. What data , logs can we collect to analyse the performance and feed back to this list? Thanks. David Leeming and Dudley ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel