MySQL cluster using ndbcluster engine under FreeBSD 11

January 22nd, 2017


Not to discourage you, but make sure you read and understand MySQL cluster limitations thoroughly prior to start building the cluster. You don’t want to spend time on building the whole thing just to discover at the very end that you hit some hard coded limitation that can’t be resolved. It’s very easy to be trapped into Catch-22 here: some third-party vendor might say “why would we want to adjust our software to overcome MySQL limitations?”, and I’m sure MySQL dev team has had valid reasons to introduce those. So you end up in the middle, and you’re basically stuck.

For example, the vanilla typo3 distribution won’t work with ndbcluster engine out of the box. You hit the Row size limitation almost immediately, and unless you’re willing to spend time to analyze and optimize the structure of the typo3 database you’re blocked. You might be lucky, and it could be just a small change from varchar(2000) to varchar(1000), but you might be not. In addition to that, you’ll most certainly need a separate instance of MySQL with InnoDB or MyISAM, so you can import the DB, dump it, and start feeding it to the ndbcluster engine in batches. All these contribute to the time spent, and during the course of the installation you start considering alternatives, like changing the Operating System, and/or trying Galera for instance, or even switching to PostgreSQL altogether, but we’re not looking for easy paths, are we? :)

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NSD and OpenDNSSEC under FreeBSD 10 [Part 5: SafeNet HSM]

May 18th, 2016

This is the fifth part in the series of articles explaining how to run NSD and OpenDNSSEC under FreeBSD 10.

This time we’re going to integrate proper hardware HSM support in our setup — a pair of SafeNet Network HSMs (aka Luna SA).

Here is how our updated installation diagram looks like:


Before we jump into technical details there are a couple of assumptions:

— I assume that HSMs are already configured and partitioned. HSM installation is outside of scope of this guide since it’s a lengthy and pretty time consuming process which has nothing to do with OpenDNSSEC. It also involves a big chunk of work to be done on the access federation field (different teams accessing different partitions with different PEDs or passwords). SafeNet HSM’s documentation is quite solid though, so make sure this part is completed. In our setup, both HSMs run the latest software 6.2.0-15 and there is one partition created on both units called TEST. TEST partition is activated and we’re going to create High Availability group, add both HSMs to the HA group and allow NS-SIGN to access it;

— As you might have noticed, I decided to leave ZSKs to be handled by SoftHSM. One of the things that you’ll have to keep an eye on with network HSMs is the HDD space. The way it works with SafeNet is that you have an appliance with some fixed amount of disk space (let’s say 2MB). Then you create partitions and allocate space out of total amount for each partition (by default it’s equal distribution). So let’s assume we created five partitions 417274 bytes each. Normally, storing a pair of public/private key consumes very little, but with OpenDNSSEC we’re talking about a number of domains each storing a pair of public/private keys for both KSK and ZSK. It’s very important to understand how far you can go, so you’re not surprised after several years when you discover that you run out of space.

Let’s do some basic math: one domain, with both ZSK (1024) and KSK (2048) stored on HSM, will consume 2768 bytes, so with 417274 bytes partition you should be able to handle ~150 domains. However, during ZSK or KSK rollover, another pair will be temporarily created, and although ZSK/KSK rollover shouldn’t happen at the same time and OpenDNSSEC will purge expired keys after the rollover is completed, you’ll have to consider extra 2768 bytes per domain (for a period of time defined in <Purge> stanza in kasp.xml), which leaves you 75 domains. As you can see this isn’t much. That’s why I decided to keep SoftHSM for ZSKs to save some HSM space (which is not cheap to say the least!).

One of the disadvantages of keeping both storage engines is that you’ll have one more dependency to worry about should you consider to upgrade (for example to SoftHSM2), hence the choice is yours. Another option would be to store private keys in HSM and leave public keys aside (<SkipPublicKey/> option under conf.xml), but I’ve read that it’s very much dependent on the HSM provider and could lead to unexpected results. And one more option would be to use <ShareKeys/> under kasp.xml — that way you can share the same key for multiple domains.

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Viewing package ChangeLog with rpm

April 4th, 2016

Here is how to view the ChangeLog of installed package using rpm under CentOS:

  1. rpm -q —-changelog libuuid-2.23.2-26.el7_2.2.x86_64 | more
  3. * Wed Mar 16 2016 Karel Zak <> 2.23.2-26.el7_2.2
  4. – fix #1317953 – lslogins crash when executed with buggy username

Same applies to the kernel. By adding -p switch you can actually check the rpm file itself without installing it:

  1. rpm -qp —-changelog | more
  3. * Thu Mar 31 2016 Akemi Yagi <> []
  4. – Apply debranding changes
  5. – Roll in i686 mods
  6. – Modify config file for x86_64 with extra features turned on including

FreeBSD template for ManageEngine OpManager

March 18th, 2016

We use OpManager by ManageEngine to monitor our infrastructure. Most of Linux flavors are already covered by default templates in OpManager. Moreover, you’ll be able to get interface statistics and CPU/RAM utilization of FreeBSD servers with the included UCD SNMP MIBs. The only bit that was missing was the monitoring of partitions for FreeBSD, hence I decided to spend a bit of my time and finally make the template that could be used in OpManager to monitor FreeBSD servers.

It’s confirmed to work with the latest OpManager 11 (build 11600) and FreeBSD 10.x without UCD Net-SNMP installed but only bsnmp with bsnmp-ucd. The reason why bsnmp is simple: bsnmp is light and is part of the base FreeBSD, so you don’t need to install anything and bsnmp-ucd (available under /usr/ports/net-mgmt/bsnmp-ucd) is a module for bsnmpd which implements parts of UCD-SNMP-MIB, while UCD Net-SNMP requires a massive amount of dependencies to be installed.

Once bsnmp-ucd is installed you might want to enable ucd module in /etc/snmpd.config and restart bsnmpd:

  1. # UCD module
  2. begemotSnmpdModulePath."ucd" = "/usr/local/lib/"

So here we go (you can also download it from here, just make sure to change the extension to XML):

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <CustomDevicePackage>
  3. <CustomDevicePackage deviceType="FreeBSD" iconName="linux.png" pingInterval="5">
  4. <SysOIDs>
  5. <SysOID oid="."/>
  6. </SysOIDs>
  8. <Graph SaveAbsolutes="false" YAXISTEXT="Percentage" customGraph="false" description="Monitors the Memory utilization based on UCD SNMP MIB" displayName="Memory Utilization(UCD SNM MIB)" failureThreshold="1" graphID="966" graphName="Lin-MemoryUtilization" graphType="node" isNumeric="true" oid="(.*100/." period="900" protocol="SNMP" sSave="true" timeAvg="false">
  10. </Graph>
  11. <Graph SaveAbsolutes="false" YAXISTEXT="Percentage" customGraph="false" description="Monitors the CPU Utilization based on UCD SNMP MIB" displayName="CPU Utilization(UCD SNMP MIB)" failureThreshold="1" graphID="315" graphName="Lin-CPUUtilization" graphType="node" isNumeric="true" oid="." period="900" protocol="SNMP" sSave="true" timeAvg="false">
  12. <OTHEROIDS/>
  13. </Graph>
  14. <Graph DisplayColumn="." Index="." SaveAbsolutes="false" YAXISTEXT="Percentage" customGraph="false" description="Monitoring the usage in each partition of the FreeBSD Device." displayName="Partition Details of the FreeBSD Device (%)" failureThreshold="1" graphID="252000" graphName="BSDPartitionWiseDiskDetails" graphType="multiplenode" isNumeric="true" oid="(.*100/." period="900" protocol="SNMP" sSave="true" timeAvg="false">
  15. <OTHEROIDS/>
  16. </Graph>
  18. <Category name="Server"/>
  19. <Vendor name="net-snmp"/>
  20. <Version version="2016031804"/>
  21. </CustomDevicePackage>
  22. </CustomDevicePackage>

Noteworthy sections:

SysOID oid=: this is the FreeBSD system identifier. When you’re going to add a new FreeBSD server the template will be automatically attached based on SysOID.

CPU and RAM sections were copied from the standard Linux template.

DisplayColumn=: . is a list of available partitions (/, /usr, /var, etc.).

Index=: . is a list of IDs of available partitions.

oid=: (.*100/. is used to calculate the percentage of utilization of a particular partition, where . is used space and . is available space.

Hope it helps.

Unattended installation of CentOS 7 with Kickstart

March 13th, 2016

While setting up my first Hadoop cluster I faced with the dilemma of how to perform installations of CentOS 7 on multiple servers at once. If you have 20 data nodes to deploy, anything you chose to automate an installation will greatly reduce the deployment time, but most importantly, it will eliminate the possibility of human error (typo for example).

Initially, I started looking at the disk cloning direction. Since all my data nodes are identical, I was thinking to prepare one data node server, then dd the system drive, place it on a NFS share, boot the server and re-image the system drive using dd image from the share. Clonezilla and DRBL seem to be the perfect pair for a such scenario. And although you will spend some time configuring, testing and tuning it, it was still worth to look into it.

Then I realized that even if I manage to establish the setup above, I’ll still have to deal with manual post-installation tweaks, like regeneration of SSH keys and probably adjusting of MAC addresses. On top of that, to transfer raw dd image (in my case it was ~30GB) might take longer than initial installation itself. Therefore I ended up using Kickstart method. I’m pretty sure there are more efficient solutions and if you happen to know one I’d love to hear your comments.

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How to configure vLAG on a Brocade VDX 6740T-1G switch to work with SafeNet Network HSM

January 26th, 2016

Caution! I deleted my previous post on how to configure vLAG on Brocade VDX 6740T-1G switch to work with SafeNet Network HSM because actually it didn’t work as it should. If you get a cached version somewhere please disregard it.

I have no idea how I managed to get bonding to operate in round-robin mode on SafeNet Network HSM:

  1. [hsm-node-1] lunash:>network interface bonding show
  3. ———————————————————–
  4. Ethernet Channel Bonding Driver: v3.4.0-2 (October 7, 2008)
  6. Bonding Mode: load balancing (round-robin)

Because once the appliance was rebooted the bonding mode has changed to active-backup and the whole story with LAGs became irrelevant. The primary interface started flapping again and the only way to stabilize connectivity to HSM was to disable the slave interface.

  1. [hsm-node-1] lunash:>network interface bonding show
  3. ———————————————————–
  4. Ethernet Channel Bonding Driver: v3.4.0-2 (October 7, 2008)
  6. Bonding Mode: fault-tolerance (active-backup)

So, back to the original subject of the post: how do you configure a LAG on Brocade switch to work with SafeNet Network HSM? The answer is — you don’t. In fault-tolerance bonding mode, when one interface is active and another one is backup (read passive), you don’t create any LAGs on the switch. All you have to do is to bring both interfaces to switchport mode access mode and ensure that VLAN and speed settings are identical. Here is how our switch config looks like:

  1. !
  2. interface TenGigabitEthernet 12/0/2
  3.  speed 1000
  4.  description -=HSM-NODE-1:ETH0=-
  5.  switchport
  6.  switchport mode access
  7.  switchport access vlan 12
  8.  spanning-tree shutdown
  9.  no fabric isl enable
  10.  no fabric trunk enable
  11.  no shutdown
  12. !
  13. interface TenGigabitEthernet 13/0/2
  14.  speed 1000
  15.  description -=HSM-NODE-1:ETH1=-
  16.  switchport
  17.  switchport mode access
  18.  switchport access vlan 12
  19.  spanning-tree shutdown
  20.  no fabric isl enable
  21.  no fabric trunk enable
  22.  no shutdown
  23. !

Now, you certainly lose link aggregation and load balancing functionalities, because only one interface will be passing traffic at a time. The slave interface comes into play only if the primary interface is down. We’re still good though when it comes to redundancy — you can disconnect the cable from ETH0 without any impact on connectivity.

On a HSM side, you don’t have many options so you follow the standard procedure: assign the IP address to the bond (network interface bonding config -ip x.x.x.x -netmask y.y.y.y -gateway z.z.z.z) and bring it up (network interface bonding enable).

To check the status:

  1. [hsm-node-1] lunash:>network interface bonding show
  3. ———————————————————–
  4. Ethernet Channel Bonding Driver: v3.4.0-2 (October 7, 2008)
  6. Bonding Mode: fault-tolerance (active-backup)
  7. Primary Slave: eth0 (primary_reselect failure)
  8. Currently Active Slave: eth1
  9. MII Status: up
  10. MII Polling Interval (ms): 100
  11. Up Delay (ms): 2000
  12. Down Delay (ms): 0
  14. Slave Interface: eth0
  15. MII Status: up
  16. Speed: 1000 Mbps
  17. Duplex: full
  18. Link Failure Count: 0
  19. Permanent HW addr: 00:15:c4:n7:13:06
  21. Slave Interface: eth1
  22. MII Status: up
  23. Speed: 1000 Mbps
  24. Duplex: full
  25. Link Failure Count: 0
  26. Permanent HW addr: 00:15:c4:n7:6a:34
  27. ———————————————————–
  28. ———————————————————–
  29. Status for eth0:
  30.         Link detected: yes
  32. Status for eth1:
  33.         Link detected: yes
  34. ———————————————————–
  36. Command Result : 0 (Success)
  1. [hsm-node-1] lunash:>status interface
  3. bond0     Link encap:Ethernet  HWaddr 00:15:C4:N7:13:06
  4.           inet addr:  Bcast:  Mask:
  6.           RX packets:13479 errors:0 dropped:0 overruns:0 frame:0
  7.           TX packets:3183 errors:0 dropped:0 overruns:0 carrier:0
  8.           collisions:0 txqueuelen:0
  9.           RX bytes:1059045 (1.0 MiB)  TX bytes:446623 (436.1 KiB)
  11. eth0      Link encap:Ethernet  HWaddr 00:15:C4:N7:13:06
  12.           UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
  13.           RX packets:12670 errors:0 dropped:0 overruns:0 frame:0
  14.           TX packets:2082 errors:0 dropped:0 overruns:0 carrier:0
  15.           collisions:0 txqueuelen:1000
  16.           RX bytes:996811 (973.4 KiB)  TX bytes:300205 (293.1 KiB)
  17.           Interrupt:58 Memory:fb4c0000-fb4e0000
  19. eth1      Link encap:Ethernet  HWaddr 00:15:C4:N7:6A:34
  20.           UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
  21.           RX packets:809 errors:0 dropped:0 overruns:0 frame:0
  22.           TX packets:1101 errors:0 dropped:0 overruns:0 carrier:0
  23.           collisions:0 txqueuelen:1000
  24.           RX bytes:62234 (60.7 KiB)  TX bytes:146418 (142.9 KiB)
  25.           Interrupt:169 Memory:fb6e0000-fb700000
  27. Command Result : 0 (Success)

How to configure SNMP on a Brocade VDX 6740T-1G switch

January 25th, 2016

Below is a snippet of the config that worked for me to allow SNMP v1 polling of a Brocade VDX 6740T-1G switch. Nothing fancy, I just wanted to enable read-only, SNMP v1 access to the switch to start capturing the load of the interfaces. Note that the NOS version is 6.0.2.

  1. snmp-server contact "Your network crew"
  2. snmp-server location "DC A"
  3. snmp-server sys-descr "Brocade VDX 6740T-1G"
  4. snmp-server community XXXXX groupname monitor
  5. snmp-server view monitor 1.3.6 included
  6. snmp-server group monitor v1 read monitor

The first three lines are not interesting. The forth and the last one will enable SNMP v1 read-only access. Note that you have to specify a groupname. You can name it whatever you like but it has to be consistent.

Finally, without ‘snmp-server view monitor 1.3.6 included’ line you will be able to poll the switch but no data will be returned. Perhaps it could be useful if you have multiple teams and you want to separate who can monitor what, but since I don’t need it I allowed access to the whole MIB.

How to add a license to a Brocade VDX6740T-1G switch

January 24th, 2016

In order to license a particular feature on a Brocade VDX 6740T-1G switch you’ll need:

  • transaction key (22 characters long string received from your Brocade supplier, which is bound to a particular feature, for example BR-VDX6740T-1G-16X10G-COD (to add 16x10GB Capacity on Demand feature) or BR-VDX6740-2X40G-POD (to unlock two remaining QSFP ports));
  • access to the Brocade portal (Software Licensing section);
  • license ID of the switch where the license is going to be attached to.

To get a license ID, log in to the switch and run:

  1. show license id rbridge-id 12
  3. ===================================================
  4.   12                    XX:XX:XX:XX:XX:XX:XX:XX

Since all my VDXs are in a VCS Logical Chassis mode, I have to specify the rbridge-id of the member.

Login to the Brocade portal, go to Software Licensing and enter the transaction key. On the next page you’ll be prompted for an email address and the license ID.

Once generated, you’ll receive a XML file with the long string between licKey tags.

Copy it (omit licKey tags) and execute on the switch:

  1. license add rbridge-id 12 licStr "XX XXXXXXXX#"

Make sure to place the license inside quotes, since normally there is a space in the license key.

To check whether the license was deployed run:

  1. show license rbridge-id 12
  3. rbridge-id: 12
  4. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  5.        10G Port Upgrade license
  6.        Feature name:PORT_10G_UPGRADE
  7.        License is valid
  8.        Capacity: 16

Booting F5 BIG-IP LTM 3900 from USB

November 8th, 2015

As a side note: should you own BIG-IP LTM 3900 appliance and wonder how to boot it from the USB stick (to reinstall the OS or run the End User Diagnostics software) make sure to use a USB stick which is precisely 1GB in size. Any other USB sticks (2/4/8/16GB) simply won’t work.

Why it can’t be documented somewhere on the F5 website remains a mystery to me.

[20151205] : I stand corrected. It looks like it has nothing to do with the size but with the chipset. I received a Rescue Kit the other day from F5 and they included two USB 32GB sticks — it’s SanDisk Cruzer Glide.

Adding and troubleshooting KMS keys

October 29th, 2015

On the KMS host:

Use Volume Activation Tools to add a new host key or:

  1. cscript.exe c:\windows\system32\slmgr.vbs -ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

To see what keys have been deployed and what the status is:

  1. cscript.exe c:\windows\system32\slmgr.vbs /dlv all

To activate (requires http/s access from the KMS host):

  1. cscript.exe c:\windows\system32\slmgr.vbs /ato activation.ID

where Activation ID is a string you get from running ‘cscript slmgr.vbs /dlv all’.

On the KMS client:

To manually force the activation of Windows OS (requires 1688/tcp access to the KMS host):

  1. cscript.exe c:\windows\system32\slmgr.vbs /ato

To manually force the activation of Windows Office (requires 1688/tcp access to the KMS host):

  1. cscript.exe c:\"program files (x86)"\"microsoft office"\office14\ospp.vbs /act