Performance debugging


  • Discourse touched me in a no-no place

    So for the past week I have been trying to backtrack awful performance in our test environment and only our test environment.

    No luck. At all. In the production environment, everything is great. In dev, everything is great. In test, every single component wants 100 percent CPU.

    Eventually I resorted to staring at the Taskmanager. And when I saw the problem, I shat bricks.



  • @Weng said:

    And when I saw the problem, I shat bricks.

    Is this supposed to be obvious?



  • Test underpowered compared to prod?


  • Discourse touched me in a no-no place

    Little bit.


  • Impossible Mission Players - A

    Lol, who has only one core nowadays?


  • Discourse touched me in a no-no place

    VM. The CPUID indicates that the underlying host has 4 cores... And is 7 years old.



  • Is your PrtSrc key broken?


  • Impossible Mission Players - A

    @Weng said:

    7 years old.
    For some reason this prompted me to check on some of my VMs as well. I found one of them like this:

    Considering that this one is supposed to be Static IP in an excluded block in DHCP, I'm not sure how this should happen.
    Unless some idiot decided to plug in a consumer router in backwards to the network....


    Filed under: Some strong words are a brewing...


  • Discourse touched me in a no-no place

    My work PC is in a security bubble. Wooden table is the only safe way.


  • Winner of the 2016 Presidential Election

    Did.... did you RDP with an address conflict? Or did you access it some other way?


  • Impossible Mission Players - A

    It's a screenshot of the VM taken through the management interface.
    Apparently that dialog box happened sometime in the recent six months and nobody's been there to click it away.

    I'm assuming that whatever device that triggered it is long gone. ;)


  • Winner of the 2016 Presidential Election

    @Tsaukpaetra said:

    It's a screenshot of the VM taken through the management interface.
    Apparently that dialog box happened sometime in the recent six months and nobody's been there to click it away.

    I'm assuming that whatever device that triggered it is long gone. ;)

    Ah, OK. I was slightly confused as to how you successfully initiated an RDP connection if the IP was in conflict...


  • Impossible Mission Players - A

    @sloosecannon said:

    successfully
    Oh, well first I had to boot this old XP machine that had a version of MSTSC.exe that didn't complain when your RDP session has no security.........


  • Discourse touched me in a no-no place

    Multiple IPs. It'll toss that box for any one of them, and accept rdp on any.


  • Winner of the 2016 Presidential Election

    @Tsaukpaetra said:

    RDP session has no security.........

    :baggage_claim:

    Filed Under: I tried to do :gag:


  • Impossible Mission Players - A

    Well if that's all it takes to make you want to :left_luggage: , I won't mention that this machine iswas the PDC, and that it automatically logged into the administrator account (for a "server" application that needs a full desktop session to run, so it can put a golden :key: icon in the tray).

    I also won't tell you that it iswas the master DHCP and DNS server for the domain as well. And the primary file server. And the database server. And the thing most likely to be attacked first during a network intrusion due to it having the dubious privilege of having the IP address of 192.168.1.1.


    Filed under: Much of it was moved to a new VM running Server 2012, but this one still chugs along for that stupid golden key that I refuse to put on the new server.


  • Discourse touched me in a no-no place

    @Tsaukpaetra said:

    for a "server" application that needs a full desktop session to run, so it can put a golden :key: icon in the tray

    Ha. We have a desktop app that has an automation feature. We have a service that watchdogs the applications process (and implements stuff like "stop it, I need to run it in an actual session"). It happily runs in a headless service session without even the user profile loaded,despite being a VB5 app (you can tell by the UI widgets).

    It performs the same function just as well as gazillion dollar specialist server apps, but it costs 300 bucks a seat. We even asked if they wanted more money to support our bizarre use case. They declined and said they only needed 1 seat for that.


  • Impossible Mission Players - A

    @Weng said:

    It happily runs in a headless service session without even the user profile loaded
    Thing is, this app should totally be able to do the same. It doesn't access the user session, just the configuration files in the program's directory (which must be shared world-read/write to all clients on the network), and the only thing that UI is for is to load up a new License Key (hence the icon) and see status of said key (as far as how many clients are active etc.).

    Trouble is, it's not our program, and the ones who made it claim that this is the only solution to get it to run. Granted, their main client-side installer still believes our computers are running Vista :wtf:, so whatever.

    Stupid thing doesn't even need a UI, it should be happy as a service logging to wherever (since half of it is driven by file events in its program directory, even the "management" aspect shouldn't be a big deal either).

    Sadly, this is the world I participate in...



  • I don't know. Sometimes I've gotten this message, even though I'm in a home network with like 5 devices, all set to DHCP autoconfig and none having had their network settings touched for a year.


  • Impossible Mission Players - A

    @anonymous234 said:

    none having had their network settings touched for a year.
    IME this happens most often when resuming from sleep/hibernation, and the box just assumes that it can have its "preferred IP" without recourse and without asking the DHCP server. If enough time has passed that said DHCP server has handed out that IP to another computer (due to it being free due to lease expiration), this can easily happen.



  • Reminds me of a time that a DEC machine was unreachable on the network. I was ordered in to replace the NIC.

    As I habitually ignored the recommendations of first and second line support (and my third line support guy endorsed this for raisons) I investigated.

    DecNet was fine - no NIC issues here, so I started interrogating the IT drones. Turns out somebody had reallocated the IP of the machine to a router.

    Other fun to be had was the argument / discussion as to why I was still on site as it was a simple board swap. But that is part of another story



  • @Tsaukpaetra said:

    Apparently that dialog box happened sometime in the recent six months and nobody's been there to click it away.

    Ah those wishy-washy mousey-clicky WIMP OSes.
    Fuck them.



  • Yeah. That's when I discovered my router had a default DHCP lease of something incredibly short - like 1 hr. I pushed that up to the max the router allowed.


  • Impossible Mission Players - A

    @dcon said:

    something incredibly short

    :giggity:

    It's nice in situations where it's needed, like in a cable modem that hasn't sync'd up with the ISP so it doesn't actually have a real IP address for you (1 minute leases are really hot at that point), but in this case...


  • sockdevs

    @dcon said:

    Yeah. That's when I discovered my router had a default DHCP lease of something incredibly short - like 1 hr. I pushed that up to the max the router allowed.

    mine is set to 65535

    i'm not sure what 65535 represents but it was as big as the router would let me set the TTL of the lease....



  • I think TTL is traditionally in minutes? At least, that's what it is for domains...


  • sockdevs

    @LB_ said:

    I think TTL is traditionally in minutes? At least, that's what it is for domains...

    could be seconds as well.

    i don't really know nor care as it's as high as my router will let me set it. ;-)



  • Mine's set to... whatever the default is (1 day).
    Anything where the IP needs to always be the same has the address reserved, no other devices IP address matters.



  • I usually set mine to as long as I can(probably a month)... It'll take a while before I use 200 ips, with like 30 devices including vms..


  • Impossible Mission Players - A

    @loopback0 said:

    always be the same has the address reserved

    Yep. It's why my reservation table is two pages long. Only the <abbr title="and there are exceptions to those, as some of them are "servers" because raisins">phones and laptops are really on DHCP.

    One of these days I'm going to expand the block...



  • @Tsaukpaetra said:

    It's why my reservation table is two pages long.

    At home?! :wtf:


  • Impossible Mission Players - A

    Sure.

    Some of the phones are in a specific block that's not cut off the internet after bed-time.



  • Shitting hell :laughing:



  • Ah, that reminds me of the Good Ol' Days(TM), and a little bug feature in Windows XP.

    You see, back in the dark ages, Microsoft determined that it should pre-schedule future DHCP renewals upon receiving a lease response back from the local DHCP server. And, as per the DHCP specification, those renewals should be scheduled at 50%, 75%, and 87.5% of the full duration of the lease. But the little algorithm that couldn't which handled XP's DHCP Client didn't really handle renewal times that weren't a whole number of minutes in the future. So, if you were using a lease time of, say, 1700 seconds (like some networking hardware the ISP I worked at used as a default in their release in 2010), and XP was pre-SP3, the DHCP Client would just shit the bed and throw the lease away.

    There was actually Microsoft documentation at the time that strongly suggested you use whole day increments for your lease times, in case you had to support underpatched systems.

    Makes me long for the days when all leases had to be multiples of 86400 seconds. And when the damn kids stayed off my lawn...



  • @Tsaukpaetra said:

    @dcon said:
    something incredibly short

    :giggity:

    It's true! :cry:


  • Winner of the 2016 Presidential Election

    @Tsaukpaetra said:

    the configuration files in the program's directory (which must be shared world-read/write to all clients on the network)

    This seems like a good reason to keep it separated even if the golden :key: issue were fixed.

    @Tsaukpaetra said:

    Only the phones and laptops are really on DHCP.

    FTFY.


  • Impossible Mission Players - A

    ''servers'' because raisins

    You have no idea. Allow me to illuminate:

    For the primary fileshare/webserver/media server the upgrade path went like so:

    1. NSLU2 device attached to 500 GB USB disk
    2. Wifi-connected (because raisins) IBM T42 laptop, with 1TB disk as secondary drive
    3. Actual server running FreeNAS in Raid Z2 (4 disks) for 8 TB total space

    Before the Virtualize All The Things! event, quite a few things were distributed across multiple devices and machines because I have crappy PCs and one-pc-to-rule-them-all wasn't capable yet.

    Fun times I live in...


    Filed under: Oh, and let me tell you about the overall network infrastructure...



  • Perhaps I'm living in a timepod, but for those devices where I care about their IP address not changing, I allocate them a static one from a pool of address my DCHP Server does not know about.


  • Impossible Mission Players - A

    Yeah, for some reason I couldn't get that to work properly with dd-wrt's dnsmasq, so this was the result.
    At least I got it to stop mixing leases with the static-zonepool.



  • Sometimes you lose sight of the larger things, because little things are blocking the view - this is a general apology for raisons.

    One of the nice things about recent network devices is the inclusion of a web based I/F, so you can configure and control them far more easily.

    One of the bad things about recent network devices is the inclusion of a web based I/f, because you are restrained in what you can do by the scope and quality of it.

    I have a LAN Drive, well more of a cute linuxy controlled 4TB thingy from WD. I made a mistake in getting it as a substitute for what I actually wanted, as "it" is geared toward "it" being a media Cloud device.

    Long story short: "puttied" across to it, knobbled the built in "media server", enabled samba. Result!

    So it just occurred to me to try the same with some other network devices and see if they are linuxy "boxes"


  • Impossible Mission Players - A

    @loose said:

    from WD
    Great minds think alike? Story sharing time!

    I got a WD Wireless Passport for the explicit purpose of syncing music to my Car PC which (for legacy raisins) can't connect wifi outside of the cabin. This device apparently has a few services, like a tiny web server, twonky, samba, and ftp (in addition to the USB 3.0 port, which allows "direct" connection to the HD). It also coincidentally has an sshd that can be enabled in the web interface (score!).

    So instead of the remarkably complicated Windows Shared Folder Partnership thing I was planning on setting up, I shell in, write up a few scripts to bootstrap OptWare (kinda, I'm not that good as shell scripting in Linux), download btsync, and link up the folder with said Car PC (and the source server in the house).

    Due to how the device bridges wifi networks, I just leave it inside the house so it syncs up the library, then bring it into the car to let it sync with the car.

    Mission accomplished! :sunglasses:



  • @Tsaukpaetra said:

    my Car PC

    :exclamation:



  • I always wondered why people install PCs in their car. What does it gain that you can actually use while driving that, say, a smartphone doesn't provide, or that can't be done by installing a media/satnav headunit?


  • Discourse touched me in a no-no place

    Geek cred. Also, media head units are almost uniformly terrible.



  • @Weng said:

    Geek cred

    Ah, ePeen, of course.

    @Weng said:

    Also, media head units are almost uniformly terrible.

    The one in my car isn't which, despite being a VW unit, still cost less money and time to retrofit than a PC would have done.


  • Discourse touched me in a no-no place

    I'll have to tell you guys about the telemetry package I'm building for the racecars.



  • @loopback0 said:

    The one in my car isn't which, despite being a VW unit, still cost less money and time to retrofit than a PC would have done.

    It's 'cause of all the money they saved on meeting emissions requirements.


  • Impossible Mission Players - A

    @loopback0 said:

    The one in my car isn't which, despite being a VW unit, still cost less money and time to retrofit than a PC would have done.

    Not sure,

    • $25 pos laptop
    • $20 cables and wires
    • $120 screen and touch interface

    It's not that bad, and it can do all sorts of things a dumb head unit can't (like wardrive) .



  • @Tsaukpaetra said:

    (like wardrive)

    I have no use for that in a car? I've never been sure who would, bar people up to no good.



  • One of my daydreams, or ambitions, is to be able to access the ECU in order to tweak things on demand so to speak. You can get really small PCs these days and wireless input and stuff, they can be stashed anywhere.


Log in to reply
 

Looks like your connection to What the Daily WTF? was lost, please wait while we try to reconnect.