802.3ad (mode=4) bonding for RAC interconnects
Is anyone using 802.3ad (mode=4) bonding for their RAC interconnects? We have five Dell R710 RAC nodes and we're trying to use the four onboard Broadcom NetXtreme II NICs in a 802.3ad bond with src-dst-mac load balancing. Since we have the hardware to pull this off we thought we'd give it a try and achieve some extra bandwith for the interconnect rather than deploying the traditional acitve/standby interconnect using just two of the NICs. Has anyone tried this config and what was the outcome? Thanks.
I don't but may be the documents might help ?
http://www.iop.org/EJ/article/1742-6596/119/4/042015/jpconf8_119_042015.pdf?request-id=bcddc94d-7727-4a8a-8201-4d1b837a1eac
http://www.oracleracsig.org/pls/apex/Z?p_url=RAC_SIG.download_my_file?p_file=1002938&p_id=1002938&p_cat=documents&p_user=nobody&p_company=994323795175833
http://www.oracle.com/technology/global/cn/events/download/ccb/10g_rac_bp_en.pdf
Edited by: Hub on Nov 18, 2009 10:10 AM
Similar Messages
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Teamed NICs for RAC interconnect
Hi there,
We have an Oralce 10g RAC with 2 nodes. there are only one NIC for RAC interconnect in both servers.
now we want to add one redundant NIC into each server for RAC interconnect as well.
Could you please guide me some documents about this "teamed NICs for RAC interconnect "?
Your help is greatly appreciated!
Thanks,
ScottSearch around for NIC bonding. The exact process will depend on your OS.
Linux, see Metalink note 298891.1 - Configuring Linux for the Oracle 10g VIP or private interconnect using bonding driver
Regards,
Greg Rahn
http://structureddata.org -
Dedicated switches needed for RAC interconnect or not?
Currently working on an Extended RAC cluster design implementation, I asked the network engineer for dedicated switches for the RAC interconnects.
Here is a little background:
There are 28 RAC clusters over 2X13 physical RAC nodes with separate Oracle_Home for each instance with atleast 2+ instances on each RAC node. So 13 RAC nodes will be in each site(Data-Center). This is basically an Extended RAC solution for SAP databases on RHEL 6 using ASM and Clusterware for Oracle 11gR2. The RAC nodes are Blades in a c7000 enclosure (in each site). The distance between the sites is 55+ kms.
Oracle recommends to have Infiniband(20GBps) as the network backbone, but here DWDM will be used with 2X10 Gbps (each at 10 GBps) links for the RAC interconnect between the sites. There will be separate 2x1GBps redundant link for the Production network and 2x2 GBps FC(Fiber-Channel) redundant links for the SAN/Storage(ASM traffic will go here) network. There will be switches for the Public-production network and the SAN network each.
Oracle recommends dedicated switches(which will give acceptable latency/bandwith) with switch redundancy to route the dedicated/non-routable VLANs for the RAC interconnect (private/heartbeat/global cache transfer) network. Since the DWDM interlinks is 2x10Gbps - do I still need the dedicated switches?
If yes, then how many?
Your inputs will be greatly appreciated.. and help me take a decision.
Many Thanks in advance..
AbhijitAbsolutely agree.. the chances of overload in a HA(RAC) solution and ultmate RAC node eviction are very high(with very high latency) and for exactly this reason I even suggested inexpensive switches to route the VLANs for the RAC interconnect through these switches. The ASM traffic will get routed through the 2x2GB FC links through SAN-Directors (1 in each site).
Suggested the network folks to use Up-links from the c7000 enclosure and route the RAC VLAN through these inexpensive switches for the interconnect traffic. We have another challenge here: HP has certified using VirtualConnect/Flex-Fabric architecture for Blades in c7000 to allocate VLANs for RAC interconnect. But this is only for one site, and does not span Production/DR sites separated over a distance.
Btw, do you have any standard switch model to select from.. and how many to go for a RAC configuration of 13 Extended RAC clusters with each cluster hosting 2+ RAC instances to host total of 28 SAP instances.
Many Thanks again!
Abhijit -
RAC Interconnect Transfer rate vs NIC's Bandwidth
Hi Guru,
I need some clarification for RAC interconnect terminology between "private interconnect transfer rate" and "NIC bandwidth".
We have 11gR2 RAC with multiple databases.
So we need to find out what the current resource status is.
We have two physical NICs each node. And 8G is for public and 2G is for private (interconnect).
Technically, we have 4G for Private network bandwidth.
If I look at the "Private Interconnect Transfer rate" though OEM or IPTraf (linux tool), it is showing 20 ~30 MB/Sec.
There is no any issue at all at this moment.
Please correct me if I am wrong.
The transfer rate will be fine till 500M or 1G/Sec. Because the current NIC's capacity is 4G. Does it make sense ?
I'm sure there are multiple things to consider,but I'm kind of stumped on the whole transfer rate vs bandwidth. Is there any way to calculate what a typical transfer would be....
OR How do I say our interconnect are good enough ....based on the transfer rate ?
Another question is ....
In our case, how do I set up the warning threshold and Critical threshold for "Private Interconnect Transer rate" in OEM ?
Any comments will be appreciated.
Please advise.Interconnect performance sways more to latency than bandwidth IMO. In simplistic terms, memory is shared across the Interconnect. What is important for accessing memory? The size of the pipe? Or the speed of the pipe?
A very fast small pipe will typically perform significantly better than a large and slower pipe.
Even the size of the pipe is not that straight forward. Standard IP MTU size is 1500. You can run jumbo and super-jumbo frame MTU sizes on the Interconnect - where for example a MTU size of 65K is significantly larger than a 1500 byte MTU. Which means significantly more data can be transferred over the Interconnect at a much reduced overhead.
Personally, I would not consider Ethernet (GigE included) for the Interconnect. Infiniband is faster, more scalable, and offers an actual growth path to 128Gb/s and higher.
Oracle also uses Infiniband (QDR/40Gb) for their Exadata Database Machine product's Interconnect. Infiniband also enables one to run Oracle Interconnect over RDS instead of UDP. I've seen Oracle reports to the OFED committee saying that using RDS in comparison with UDP, reduced CPU utilisation by 50% and decreased latency by 50%.
I also do not see the logic of having a faster public network and a slower Interconnect.
IMO there are 2 very fundamental components in RAC that determines what is the speed and performance achievable with that RAC - the speed, performance and scalability of the I/O fabric layer and for the Interconnect layer.
And Exadata btw uses Infiniband for both these critical layers. Not fibre. Not GigE. -
RAC interconnect using UDP - default ports?
Is there a default port used by each cluster member to listen for connections over UDP? We use IPTABLES firewalls on our hosts, and I need to ensure the cluster heartbeat traffic gets through the firewall properly.
Thanks in advance.
Jeffuser2528460 wrote:
I understood the UPD ports that are going to be used on the interconnect (clearly without a firewall). Is there a set of default ports?I did a quick count (using <i>lsof</i> to list UDP ports opened on the Interconnect interface) that showed over 185 UDP ports in use.. E.g.
[root ~]# lsof -n -i | grep UDP | grep "10.0.1.1"
oracle 5577 oracle 10u IPv4 130938 UDP 10.0.1.1:22747
oracle 5577 oracle 15u IPv4 130941 UDP 10.0.1.1:64265
oracle 5579 oracle 10u IPv4 130948 UDP 10.0.1.1:39566
oracle 5579 oracle 15u IPv4 130951 UDP 10.0.1.1:55454
oracle 5579 oracle 21u IPv4 130970 UDP 10.0.1.1:27897
oracle 5581 oracle 10u IPv4 130973 UDP 10.0.1.1:14118
oracle 5581 oracle 15u IPv4 130976 UDP 10.0.1.1:13774
oracle 5583 oracle 10u IPv4 130983 UDP 10.0.1.1:33277
oracle 5583 oracle 15u IPv4 130986 UDP 10.0.1.1:6886
..snipped..I would not be concerned about what ports are in use. The important decisions are do you use bonding for the Interconnect, do you use jumbo or super-jumbo frames (MTU sizes), and so on. The actual ports being used has no real bearing as firewalling is not applicable. -
[SOLVED] Configure LACP (802.3ad) Bond
I've set this up before on Debian and RHEL/CentOS, but I'm having zero luck under Arch. I get the interfaces bound, and I get a bond0, but its always round-robin. My /etc/modprobe.d/bonding.conf has this one line: options bonding mode=4 miion=100.
All the references I can find to bonding in Arch are for wired/wireless failover, has anyone got this to work?
Thanks.
Last edited by Hrast (2014-09-05 02:37:21)Hrast wrote:options bonding mode=4 miion=100
Assuming it's a typo, but just in case... It's "miimon", not "miion"
Are you using netctl? Share your /etc/network.d/ profile. Have you tried "mode=802.3ad" instead of "mode=4"? It shouldn't make a difference, but it might help show any problems. -
NIC teaming/bonding for interconnection
Hi to all,
We are planning for a two node Oracle RAC implementation on Windows Server and we have some doubts about interconnect. Because redundancy is not as important, and because we are limited by money Gigabit switch will be used for interconnection and for public network.
Can we get in bandwidth (load balancing) if we use NIC Bonding on one switch. Which is best?
- To buy servers with two single 1Gb port NIC’s and bond this NIC’s for interconnection and one single port NIC for public network or
- One dual port NIC (bond this NIC’s) for interconnects and one single NIC for public network?Nikoline wrote:
We are planning for a two node Oracle RAC implementation on Windows Server and we have some doubts about interconnect. Because redundancy is not as important, and because we are limited by money Gigabit switch will be used for interconnection and for public network.Keep in mind that the h/w architecture used, directly determines how robust RAC is, how well it performs, and how it meets redundancy, high availability and scalability requirements.
The wrong h/w choices can and will hurt all of these factors.
Can we get in bandwidth (load balancing) if we use NIC Bonding on one switch. No. Bonding usually does not address load balancing. You need to check exactly what the driver stack used for bonding supports.
The primary reason for bonding is redundancy. Not load balancing/load sharing.
Which is best?
- To buy servers with two single 1Gb port NIC’s and bond this NIC’s for interconnection and one single port NIC for public network or
- One dual port NIC (bond this NIC’s) for interconnects and one single NIC for public network?A server with dual 1Gb NICs will be bonded into a single bonded NIC. And that is what then must be used - the logical bonded NIC and not the individual NICs.
This means that 2 1Gb ports provide you with a single bonded port. And you need 2 ports for RAC - public and interconnect.
So you either need 4 physical ports in total to create 2 bonded ports, or 3 ports in total for 1 bonded port and 1 unbonded port.
And what about your cluster's shared storage?
This, together with the Interconnect, determines the robustness and performance of RAC. 1Gb Interconnect is already pretty much a failure in providing a proper Interconnect infrastructure for RAC.
Keep in mind that the Interconnect is used to share memory across cluster nodes (cache fusion). The purpose is to speed up I/O - making it faster for a cluster node to get data blocks from another node's cache instead of having to hit spinning rust to read that data.
Old style fibre channel technology for shared storage is dual 2Gb fibre channels. Which will be faster than your 1Gb Interconnect. How does it make sense to use an Interconnect that is slower (less bandwidth and more latency) than the actual I/O fabric layer?
Would you configure h/w for a Windows server (be that a database, web or mail server) where the logical I/O from the server's memory buffer cache for local disks is slower than actually reading that data off local disk?
Then why do this for RAC?
Last comment - over 90% of the 500 fastest and biggest clusters on this planet run Linux. 1% runs Windows. Windows is usually a poor choice when it comes to clustering. Even Oracle does not provide their Exadata Database Machine product (fastest RAC cluster in the world) on Windows - only on Linux and Solaris (and the latter only because Oracle now owns Solaris too). -
What is acceptable level of Private Interconnect Latency for RAC
We have build 3 Node RAC on RHEL5.4 on VMware.
There is node eviction problem due to loss of Network Heartbeat.
ocssd.log:[ CSSD]2010-03-05 17:48:21.908 [84704144] >TRACE: clssnmReadDskHeartbeat: node 3, vm-lnx-rds1173, has a disk HB, but no network HB, DHB has rcfg 0, wrtcnt, 2, LATS 1185024, lastSeqNo 2, timestamp 1267791501/1961474
Ping statistics from Node2 to Node1 are as below
--- rds1171-priv ping statistics ---
443 packets transmitted, 443 received, 0% packet loss, time 538119ms
rtt min/avg/max/mdev = 0.150/2.030/630.212/29.929 ms
[root@vm-lnx-rds1172 oracle]#
Can this be reason for Node eviction? What is acceptable level of of private interconnect latency for RAC ?What is acceptable level of of private interconnect latency for RAC ?Normal local network latency should be enough. By the way latency settings are very generous.
Can you check if your to-be-evicted node runs and is reachable when seeing the node eviction messages?
In addition to that: Can you check the log files of the eviced node. Check for time stamps around "2010-03-05 17:48:21.908". Make sure all systems are NTP synchronized.
Ronny Egner
My Blog: http://blog.ronnyegner-consulting.de -
Force 802.11b mode for a wireless adapter
Hello, I would like to know how to force a wireless adapter to work on the 802.11b band only (this is, make it so it does not use g/n).
ThanksButcher wrote:I don't really think that is going to help. (It does not.)
That's probably because your wifi device driver module doesn't support enforcing 802.11b mode, like my b43:
# iwconfig wlan0 modu 11b
Error for wireless request "Set modulation" (8B2F):
SET failed on device wlan0 ; Operation not supported.
Does forcing a slower rate without changing mode help, in your casee?
# iwconfig wlan0 rate 11M -
Oracle RAC Interconnect, PowerVM VLANs, and the Limit of 20
Hello,
Our company has a requirement to build a multitude of Oracle RAC clusters on AIX using Power VM on 770s and 795 hardware.
We presently have 802.1q trunking configured on our Virtual I/O Servers, and have currently consumed 12 of 20 allowed VLANs for a virtual ethernet adapter. We have read the Oracle RAC FAQ on Oracle Metalink and it seems to otherwise discourage the use of sharing these interconnect VLANs between different clusters. This puts us in a scalability bind; IBM limits VLANs to 20 and Oracle says there is a one-to-one relationship between VLANs and subnets and RAC clusters. We must assume we have a fixed number of network interfaces available and that we absolutely have to leverage virtualized network hardware in order to build these environments. "add more network adapters to VIO" isn't an acceptable solution for us.
Does anyone know if Oracle can afford any flexibility which would allow us to host multiple Oracle RAC interconnects on the same 802.1q trunk VLAN? We will independently guarantee the bandwidth, latency, and redundancy requirements are met for proper Oracle RAC performance, however we don't want a design "flaw" to cause us supportability issues in the future.
We'd like it very much if we could have a bunch of two-node clusters all sharing the same private interconnect. For example:
Cluster 1, node 1: 192.168.16.2 / 255.255.255.0 / VLAN 16
Cluster 1, node 2: 192.168.16.3 / 255.255.255.0 / VLAN 16
Cluster 2, node 1: 192.168.16.4 / 255.255.255.0 / VLAN 16
Cluster 2, node 2: 192.168.16.5 / 255.255.255.0 / VLAN 16
Cluster 3, node 1: 192.168.16.6 / 255.255.255.0 / VLAN 16
Cluster 3, node 2: 192.168.16.7 / 255.255.255.0 / VLAN 16
Cluster 4, node 1: 192.168.16.8 / 255.255.255.0 / VLAN 16
Cluster 4, node 2: 192.168.16.9 / 255.255.255.0 / VLAN 16
etc.
Whereas the concern is that Oracle Corp will only support us if we do this:
Cluster 1, node 1: 192.168.16.2 / 255.255.255.0 / VLAN 16
Cluster 1, node 2: 192.168.16.3 / 255.255.255.0 / VLAN 16
Cluster 2, node 1: 192.168.17.2 / 255.255.255.0 / VLAN 17
Cluster 2, node 2: 192.168.17.3 / 255.255.255.0 / VLAN 17
Cluster 3, node 1: 192.168.18.2 / 255.255.255.0 / VLAN 18
Cluster 3, node 2: 192.168.18.3 / 255.255.255.0 / VLAN 18
Cluster 4, node 1: 192.168.19.2 / 255.255.255.0 / VLAN 19
Cluster 4, node 2: 192.168.19.3 / 255.255.255.0 / VLAN 19
Which eats one VLAN per RAC cluster.Thank you for your answer!!
I think I roughly understand the argument behind a 2-node RAC and a 3-node or greater RAC. We, unfortunately, were provided with two physical pieces of hardware to virtualize to support production (and two more to support non-production) and as a result we really have no place to host a third RAC node without placing it within the same "failure domain" (I hate that term) as one of the other nodes.
My role is primarily as a system engineer, and, generally speaking, our main goals are eliminating single points of failure. We may be misusing 2-node RACs to eliminate single points of failure since it seems to violate the real intentions behind RAC, which is used more appropriately to scale wide to many nodes. Unfortunately, we've scaled out to only two nodes, and opted to scale these two nodes up, making them huge with many CPUs and lots of memory.
Other options, notably the active-passive failover cluster we have in HACMP or PowerHA on the AIX / IBM Power platform is unattractive as the standby node drives no resources yet must consume CPU and memory resources so that it is prepared for a failover of the primary node. We use HACMP / PowerHA with Oracle and it works nice, however Oracle RAC, even in a two-node configuration, drives load on both nodes unlike with an active-passive clustering technology.
All that aside, I am posing the question to both IBM, our Oracle DBAs (whom will ask Oracle Support). Typically the answers we get vary widely depending on the experience and skill level of the support personnel we get on both the Oracle and IBM sides... so on a suggestion from a colleague (Hi Kevin!) I posted here. I'm concerned that the answer from Oracle Support will unthinkingly be "you can't do that, my script says to tell you the absolute most rigid interpretation of the support document" while all the time the same document talks of the use of NFS and/or iSCSI storage eye roll
We have a massive deployment of Oracle EBS and honestly the interconnect doesn't even touch 100mbit speeds even though the configuration has been checked multiple times by Oracle and IBM and with the knowledge that Oracle EBS is supposed to heavily leverage RAC. I haven't met a single person who doesn't look at our environment and suggest jumbo frames. It's a joke at this point... comments like "OMG YOU DON'T HAVE JUMBO FRAMES" and/or "OMG YOU'RE NOT USING INFINIBAND WHATTA NOOB" are commonplace when new DBAs are hired. I maintain that the utilization numbers don't support this.
I can tell you that we have 8Gb fiber channel storage and 10Gb network connectivity. I would probably assume that there were a bottleneck in the storage infrastructure first. But alas, I digress.
Mainly I'm looking for a real-world answer to this question. Aside from violating every last recommendation and making oracle support folk gently weep at the suggestion, are there any issues with sharing interconnects between RAC environments that will prevent it's functionality and/or reduce it's stability?
We have rapid spanning tree configured, as far as I know, and our network folks have tuned the timers razor thin. We have Nexus 5k and Nexus 7k network infrastructure. The typical issues you'd fine with standard spanning tree really don't affect us because our network people are just that damn good. -
Network adapter for the private interface for RAC
Hi guys
This is the specification for the Network adapter for the private interface in RAC:
The network adapter for the private interface must support the user datagram protocol (UDP) using high-speed network adapters and a network switch that supports TCP/IP (Gigabit Ethernet or better).
Do you have a document where I can have more deep details about it ?
Thanksuser2931261 wrote:
This is the specification for the Network adapter for the private interface in RAC:
The network adapter for the private interface must support the user datagram protocol (UDP) using high-speed network adapters and a network switch that supports TCP/IP (Gigabit Ethernet or better).Note that TCP is also used in addition to UDP over the Interconnect. As for the statement that the NIC must support UDP - wrong statement to make. The NIC does not support UDP. The IP (Internet Protocol) stack does. The NIC supports the bottom layer of the ISO model. UDP is at layer 4.
As for your Interconnect, you have two basic choices. Gigabyte Ethernet or Infiniband.
For GigE you need of course a GigE NIC and a GigE switch, and a cable to wire the NIC into the switch.
For Infiniband you need a HCA card (e.g. Mellanox InfiniHost PCI card) and an Infiniband switch. As HCA cards are dual port, it make sense to get 2 cables and wire both ports into the switch and bond those 2 ports as a single logical NIC. You can run IPoIB (IP over Infiniband), which means that the 2 ports on the HCA will be seen by the o/s as NICs - and bonding is supported which enables you to create a single logical NIC on top of these 2 NICs and thus have full redundancy.
Also note that GigE typically is only 1Gb/s. 10 Gb/s is available, but expensive (especially the switch). Infiniband typically is QDR rate today that provides you with 40Gb/s pipes. So each port on the HCA will be 40Gb and the bonded port will thus be 2x40Gb/s.
Infiniband is a lot faster and more scalable for an Interconnect than GigE.
Also, because of the capacity and flexibility and low latency of Infiniband, you can also use it for your storage fabric layer (running your storage protocol over it).
Typically you will need to get HBA cards (dual fibre port) to wire the RAC node to the storage array's fibre channel switch. These HBA ports are 2Gb/s.
You can eliminate these HBAs and fibre cables by using a storage protocol like SRP (Scsi RDMA Protocol - RDMA=Remote Direct Memory Access) - running SRP over your Infiniband infrastructure, together with your Interconnect.
This is btw what Oracle's Database Machine and Exadata Storage servers use (and one the reasons they have broken all RAC performance records). -
Hi,
We are in the process of migrating from a 10g single instance database to 2 node RAC (Windows Server 2008 OS, EMC storage with 2 SAN swithes,…) and we have some doubts about interconnect.
We are having difficulty in selecting the correct interconnect speed for the interconnect network, difficulty in selecting the switch/switches, …
1. Because there are 2 nodes, and 4 Ethernet cables for interconnect, whether to use one or two switches? Using a switch can be a solution but a single switch become a big single point of failure.
2. Whether we can get in performance if we use 2 switches (bonding,…) ?
3. As mentioned, there are 4 Ethernet cables, is it good idea to use existing 1Gb switches that we use for public network or to buy 1Gb switches that will be used only for private interconnection?
4. Can we use simple 16 or 8 port GigE switches?
Maybe you can point me out to some GigE and SAN switches (for nodes - storage connection) which you've seen that they work without any problems with RAC.
How can we best deisgn the networks for the interconnects?
Thank in advance!user9106065 wrote:
So the best solution for interconnection would be InfiniBand or 10GigE.If you look at what Oracle itself chose for their RAC hardware product range, then yes. Infiniband is a better choice.
What do you think about InfiniBand and Windows Server OS?Last used Windows as a server o/s back in the mid 90's. :-)
No idea how robust the OFED driver stack is on Windows. It ships with Oracle Linux as Oracle uses it for their RAC products.
What is the difference in price for InfiniBand and GigE switches?About the same I would think. A 40Gb 12 to 24 port switches a few years ago were actually cheaper than a 10GigE switch of the same port count. Pricing has come down for both though. We have recently bought a couple of 32 port QDR switches at far below $10,000 a switch.
Cabling is needed and HCA (PCI) cards too. The cards are cheaper I think than HBAs (fibre channel cards). The only issue we had in this regard is getting pizza box/blade servers with 2 PCI slots for supporting both HBA and HCA. Recent server models often have only one PCI slot as oppose to the prior models of a few years ago. So when choosing a newer servers and you need both HBA and HCA, you need to make sure there are in fact 2 PCI slots in the server.
And again, can you point me out to some InfiniBand switches which you've seen that they work without any problems with 2 node RAC?Oracle used Voltaire IB (Infiniband) switches for the first Oracle Database Machine/Exadata product. The only top500 cluster in Africa is basically (almost) next door to us here in Cape Town. They are also using Voltaire switches.
If I'm not mistaken, the same Voltaire switches are OEM'ed and sold by Oracle/Sun and HP and others. I have an HP quote for about the same below $10,000 per switch price. Of course, you can get away with a much smaller switch for a 2 node RAC - and a 2nd switch is only a consideration if you can justify the cost for redundancy in the Interconnect redundancy layer.
Voltaire pretty much seems to lead the market in this respect. Cisco used to sell IB switches too - but some of these were horribly buggy (especially the ones with FC gateways). Cisco acquired TopSpin back then - we still have a couple of old 10Gb TopSpin switches (bought from Cisco) and these have been pretty rock solid through the years. But QDR (40Gb) is what one should be looking at and not the older SDR or DDR technologies.
You should be able to shop around your existing vendors (HP, Oracle/Sun, etc) for IB switches - with the exception of Cisco that no longer does IB switches (afaik). -
How can I get my AE to work in 802.11n mode with my dlink router?
Hi all,
I have a dlink 655 wireless n router that I use for my network and a recent AE with 802.11n capability that I use to connect iTunes to my home stereo.
I have a mix of computers at home and only my imac has 802.11n capability. I work alone in the day so to speed things up, I change the wireless setting on my dlink router to 802.11n only mode. Normally, it is in a mixed mode of 802.11g/n for the other non n computers on the network.
My imac connects fine when in 802.11n only mode but the AE looses connection. As it is 802.11n capable, I was wondering why this happens?
I tried checking Airport Utility for a 802.11n only mode or something similar, but didn't find anything. Will the AE only work in 802.11n mode when on the 5ghz frequency? if so, that would explain why it doesn't connect with the dlink 2.4ghz router in n mode.
Any ideas?? Thanks!Hi. Thanks for the reply. It turns out that the router was not going into n mode because of the security I set on it. I finally figured this out and the AE did connect in n mode after all.
Well at least it's working now but I feel a little bad for posting when it was my fault!!
Cheers! -
Hi,
We are facing RAC Interconnect performance problems.
Oracle Version: Oracle 9i RAC (9.2.0.7)
Operating system: SunOS 5.8
SQL> SELECT b1.inst_id, b2.value "RECEIVED",
b1.value "RECEIVE TIME",
((b1.value / b2.value) * 10) "AVG RECEIVE TIME (ms)"
FROM gv$sysstat b1, gv$sysstat b2
WHERE b1.name = 'global cache cr block receive time'
AND b2.name = 'global cache cr blocks received'
AND b1.inst_id = b2.inst_id;
INST_ID RECEIVED RECEIVE TIME AVG RECEIVE TIME (ms)
1 323849 172359 5.32220263
2 675806 94537 1.39887778
After database restart average time increases for Instance 1 and instance 2 remains similar.
Application performance degrades, restart database solves the issue. This is critical application and can not have frequent downtimes for restart.
What specific points should I check to find out to improve interconnect performance?
Thanks
Dilip Patel.Hi,
Configurations:
Node: 1
Hardware Model: Sun-Fire-V890
OS: SunOS 5.8
Release: Generic_117350-53
CPU: 16 sparcv9 cpu(s) running at 1200 MHz
Memory: 40.0GB
Node: 2
Hardware Model: Sun-Fire-V890
OS: SunOS 5.8
Release: Generic_117350-53
CPU: 16 sparcv9 cpu(s) running at 1200 MHz
Memory: 40.0GB
CPU Utilization on Node 1 is never exceeded 40%.
CPU Utilization on Node 2 is between 20% to 30%.
Application load is more Node 1 compared to Node 2.
I can observer wait event "global cache cr request" in top 5 wait events on most of the statspack report. Application faces degrade performacne after few days of restart database. No major changes done on application recently.
Statapack report for Node 1:
DB Name DB Id Instance Inst Num Release Cluster Host
XXXX 2753907139 xxxx1 1 9.2.0.7.0 YES xxxxx
Snap Id Snap Time Sessions Curs/Sess Comment
Begin Snap: 61688 17-Feb-09 09:10:06 253 299.4
End Snap: 61698 17-Feb-09 10:10:06 285 271.6
Elapsed: 60.00 (mins)
Cache Sizes (end)
~~~~~~~~~~~~~~~~~
Buffer Cache: 2,048M Std Block Size: 8K
Shared Pool Size: 384M Log Buffer: 2,048K
Load Profile
~~~~~~~~~~~~ Per Second Per Transaction
Redo size: 102,034.92 4,824.60
Logical reads: 60,920.35 2,880.55
Block changes: 986.07 46.63
Physical reads: 1,981.12 93.67
Physical writes: 28.30 1.34
User calls: 2,651.63 125.38
Parses: 500.89 23.68
Hard parses: 21.44 1.01
Sorts: 66.91 3.16
Logons: 3.69 0.17
Executes: 553.34 26.16
Transactions: 21.15
% Blocks changed per Read: 1.62 Recursive Call %: 22.21
Rollback per transaction %: 2.90 Rows per Sort: 7.44
Instance Efficiency Percentages (Target 100%)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Buffer Nowait %: 99.99 Redo NoWait %: 100.00
Buffer Hit %: 96.75 In-memory Sort %: 100.00
Library Hit %: 98.30 Soft Parse %: 95.72
Execute to Parse %: 9.48 Latch Hit %: 99.37
Parse CPU to Parse Elapsd %: 90.03 % Non-Parse CPU: 92.97
Shared Pool Statistics Begin End
Memory Usage %: 94.23 94.93
% SQL with executions>1: 74.96 74.66
% Memory for SQL w/exec>1: 82.93 72.26
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~ % Total
Event Waits Time (s) Ela Time
db file sequential read 1,080,532 13,191 40.94
CPU time 10,183 31.60
db file scattered read 456,075 3,977 12.34
wait for unread message on broadcast channel 4,195 2,770 8.60
global cache cr request 1,633,056 873 2.71
Cluster Statistics for DB: EPIP Instance: epip1 Snaps: 61688 -61698
Global Cache Service - Workload Characteristics
Ave global cache get time (ms): 0.8
Ave global cache convert time (ms): 1.1
Ave build time for CR block (ms): 0.1
Ave flush time for CR block (ms): 0.2
Ave send time for CR block (ms): 0.3
Ave time to process CR block request (ms): 0.6
Ave receive time for CR block (ms): 4.4
Ave pin time for current block (ms): 0.2
Ave flush time for current block (ms): 0.0
Ave send time for current block (ms): 0.3
Ave time to process current block request (ms): 0.5
Ave receive time for current block (ms): 2.6
Global cache hit ratio: 3.9
Ratio of current block defers: 0.0
% of messages sent for buffer gets: 3.7
% of remote buffer gets: 0.3
Ratio of I/O for coherence: 1.1
Ratio of local vs remote work: 10.9
Ratio of fusion vs physical writes: 0.0
Global Enqueue Service Statistics
Ave global lock get time (ms): 0.1
Ave global lock convert time (ms): 0.0
Ratio of global lock gets vs global lock releases: 1.0
GCS and GES Messaging statistics
Ave message sent queue time (ms): 0.4
Ave message sent queue time on ksxp (ms): 1.8
Ave message received queue time (ms): 0.2
Ave GCS message process time (ms): 0.1
Ave GES message process time (ms): 0.0
% of direct sent messages: 8.0
% of indirect sent messages: 49.4
% of flow controlled messages: 42.6
GES Statistics for DB: EPIP Instance: epip1 Snaps: 61688 -61698
Statistic Total per Second per Trans
dynamically allocated gcs resourc 0 0.0 0.0
dynamically allocated gcs shadows 0 0.0 0.0
flow control messages received 0 0.0 0.0
flow control messages sent 0 0.0 0.0
gcs ast xid 0 0.0 0.0
gcs blocked converts 2,830 0.8 0.0
gcs blocked cr converts 7,677 2.1 0.1
gcs compatible basts 5 0.0 0.0
gcs compatible cr basts (global) 142 0.0 0.0
gcs compatible cr basts (local) 142,678 39.6 1.9
gcs cr basts to PIs 0 0.0 0.0
gcs cr serve without current lock 0 0.0 0.0
gcs error msgs 0 0.0 0.0
gcs flush pi msgs 798 0.2 0.0
gcs forward cr to pinged instance 0 0.0 0.0
gcs immediate (compatible) conver 9,296 2.6 0.1
gcs immediate (null) converts 52,460 14.6 0.7
gcs immediate cr (compatible) con 752,507 209.0 9.9
gcs immediate cr (null) converts 4,047,959 1,124.4 53.2
gcs msgs process time(ms) 153,618 42.7 2.0
gcs msgs received 2,287,640 635.5 30.0
gcs out-of-order msgs 0 0.0 0.0
gcs pings refused 70,099 19.5 0.9
gcs queued converts 0 0.0 0.0
gcs recovery claim msgs 0 0.0 0.0
gcs refuse xid 1 0.0 0.0
gcs retry convert request 0 0.0 0.0
gcs side channel msgs actual 40,400 11.2 0.5
gcs side channel msgs logical 4,039,700 1,122.1 53.1
gcs write notification msgs 46 0.0 0.0
gcs write request msgs 972 0.3 0.0
gcs writes refused 4 0.0 0.0
ges msgs process time(ms) 2,713 0.8 0.0
ges msgs received 73,687 20.5 1.0
global posts dropped 0 0.0 0.0
global posts queue time 0 0.0 0.0
global posts queued 0 0.0 0.0
global posts requested 0 0.0 0.0
global posts sent 0 0.0 0.0
implicit batch messages received 288,801 80.2 3.8
implicit batch messages sent 622,610 172.9 8.2
lmd msg send time(ms) 2,148 0.6 0.0
lms(s) msg send time(ms) 1 0.0 0.0
messages flow controlled 3,473,393 964.8 45.6
messages received actual 765,292 212.6 10.1
messages received logical 2,360,972 655.8 31.0
messages sent directly 654,760 181.9 8.6
messages sent indirectly 4,027,924 1,118.9 52.9
msgs causing lmd to send msgs 33,481 9.3 0.4
msgs causing lms(s) to send msgs 13,220 3.7 0.2
msgs received queue time (ms) 379,304 105.4 5.0
msgs received queued 2,359,723 655.5 31.0
msgs sent queue time (ms) 1,514,305 420.6 19.9
msgs sent queue time on ksxp (ms) 4,349,174 1,208.1 57.1
msgs sent queued 4,032,426 1,120.1 53.0
msgs sent queued on ksxp 2,415,381 670.9 31.7
GES Statistics for DB: EPIP Instance: epip1 Snaps: 61688 -61698
Statistic Total per Second per Trans
process batch messages received 278,174 77.3 3.7
process batch messages sent 913,611 253.8 12.0
Wait Events for DB: EPIP Instance: epip1 Snaps: 61688 -61698
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc (idle events last)
Avg
Total Wait wait Waits
Event Waits Timeouts Time (s) (ms) /txn
db file sequential read 1,080,532 0 13,191 12 14.2
db file scattered read 456,075 0 3,977 9 6.0
wait for unread message on b 4,195 1,838 2,770 660 0.1
global cache cr request 1,633,056 8,417 873 1 21.4
db file parallel write 8,243 0 260 32 0.1
buffer busy waits 16,811 0 168 10 0.2
log file parallel write 187,783 0 158 1 2.5
log file sync 75,143 0 147 2 1.0
buffer busy global CR 9,713 0 102 10 0.1
global cache open x 31,157 1,230 50 2 0.4
enqueue 58,261 14 45 1 0.8
latch free 33,398 7,610 44 1 0.4
direct path read (lob) 9,925 0 36 4 0.1
library cache pin 8,777 1 34 4 0.1
SQL*Net break/reset to clien 82,982 0 32 0 1.1
log file sequential read 409 0 31 75 0.0
log switch/archive 3 3 29 9770 0.0
SQL*Net more data to client 201,538 0 16 0 2.6
global cache open s 8,585 342 14 2 0.1
global cache s to x 11,098 148 11 1 0.1
control file sequential read 6,845 0 8 1 0.1
db file parallel read 1,569 0 7 4 0.0
log file switch completion 35 0 7 194 0.0
row cache lock 15,780 0 6 0 0.2
process startup 69 0 6 82 0.0
global cache null to x 1,759 48 6 3 0.0
direct path write (lob) 685 0 5 7 0.0
DFS lock handle 8,713 0 3 0 0.1
control file parallel write 1,350 0 2 2 0.0
wait for master scn 1,194 0 1 1 0.0
CGS wait for IPC msg 30,830 30,715 1 0 0.4
global cache busy 14 1 1 75 0.0
ksxr poll remote instances 30,997 12,692 1 0 0.4
direct path read 752 0 0 1 0.0
switch logfile command 3 0 0 148 0.0
log file single write 24 0 0 13 0.0
library cache lock 668 0 0 0 0.0
KJC: Wait for msg sends to c 1,161 0 0 0 0.0
buffer busy global cache 26 0 0 6 0.0
IPC send completion sync 261 260 0 0 0.0
PX Deq: reap credit 3,477 3,440 0 0 0.0
LGWR wait for redo copy 1,751 0 0 0 0.0
async disk IO 1,059 0 0 0 0.0
direct path write 298 0 0 0 0.0
slave TJ process wait 1 1 0 18 0.0
PX Deq: Execute Reply 3 1 0 3 0.0
PX Deq: Join ACK 8 4 0 1 0.0
global cache null to s 8 0 0 1 0.0
ges inquiry response 16 0 0 0 0.0
Wait Events for DB: EPIP Instance: epip1 Snaps: 61688 -61698
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc (idle events last)
Avg
Total Wait wait Waits
Event Waits Timeouts Time (s) (ms) /txn
PX Deq: Parse Reply 6 2 0 1 0.0
PX Deq Credit: send blkd 2 1 0 0 0.0
PX Deq: Signal ACK 3 1 0 0 0.0
library cache load lock 1 0 0 0 0.0
buffer deadlock 6 6 0 0 0.0
lock escalate retry 4 4 0 0 0.0
SQL*Net message from client 9,470,867 0 643,285 68 124.4
queue messages 42,829 41,144 42,888 1001 0.6
wakeup time manager 601 600 16,751 27872 0.0
gcs remote message 795,414 120,163 13,606 17 10.4
jobq slave wait 2,546 2,462 7,375 2897 0.0
PX Idle Wait 2,895 2,841 7,021 2425 0.0
virtual circuit status 120 120 3,513 29273 0.0
ges remote message 142,306 69,912 3,504 25 1.9
SQL*Net more data from clien 206,559 0 19 0 2.7
SQL*Net message to client 9,470,903 0 14 0 124.4
PX Deq: Execution Msg 313 103 2 7 0.0
Background Wait Events for DB: EPIP Instance: epip1 Snaps: 61688 -61698
-> ordered by wait time desc, waits desc (idle events last)
Avg
Total Wait wait Waits
Event Waits Timeouts Time (s) (ms) /txn
db file parallel write 8,243 0 260 32 0.1
log file parallel write 187,797 0 158 1 2.5
log file sequential read 316 0 22 70 0.0
enqueue 56,204 0 15 0 0.7
control file sequential read 5,694 0 6 1 0.1
DFS lock handle 8,682 0 3 0 0.1
db file sequential read 276 0 2 8 0.0
control file parallel write 1,334 0 2 2 0.0
wait for master scn 1,194 0 1 1 0.0
CGS wait for IPC msg 30,830 30,714 1 0 0.4
ksxr poll remote instances 30,972 12,681 1 0 0.4
latch free 356 54 1 2 0.0
direct path read 752 0 0 1 0.0
log file single write 24 0 0 13 0.0
LGWR wait for redo copy 1,751 0 0 0 0.0
async disk IO 812 0 0 0 0.0
global cache cr request 69 0 0 1 0.0
row cache lock 45 0 0 1 0.0
direct path write 298 0 0 0 0.0
library cache pin 29 0 0 1 0.0
rdbms ipc reply 29 0 0 0 0.0
buffer busy waits 10 0 0 0 0.0
library cache lock 2 0 0 0 0.0
global cache open x 2 0 0 0 0.0
rdbms ipc message 179,764 36,258 29,215 163 2.4
gcs remote message 795,409 120,169 13,605 17 10.4
pmon timer 1,388 1,388 3,508 2527 0.0
ges remote message 142,295 69,912 3,504 25 1.9
smon timer 414 0 3,463 8366 0.0
------------------------------------------------------------- -
In the client place the architecture team wants to implement a a node RAC cluster on Sun Solaris on Oracle 10g. But in order to minimize the interconnect traffic they want applications to connect only to one node and the other node will provide fail over capability.
Though this can be achieved with less complexity thru physical standby, theoretically if in a 2 node RAC cluster if we just use one node will it eliminate interconnect traffic?
I guess that there will not be any requests from the second node for blocks held by the first node so no transfer of blocks over interconnect will take place. But still the second node has to know about the blocks held by the first node in order to recover in case the first node crashes(cache fusion?). Right?
TIA
RadKrishjust my 0.02 cents on this .. Why would you want to invest in a High Availability Solution ( RAC ) and attempt to achieve Disaster Recovery ( Failover ) through it ..
Why would you want to minimize the Interconnect traffic in the first place .. A decent Switch plus Gigabit Ethernet / Cat5 cables is all you need for the Interconnect and its known to work well with most types of RAC Setup's ..
With Dynamic Resource Remastering , mastership of blocks across the active nodes get distributed based on access patterns .. so with your kind of setup , almost all the blocks would be mastered on Node:1 after a period of sustained activity .. Further Instance recovery happens using information from the Redo Log Thread of the crashed Node so it should not affect Interconnect traffic ..
Vishwa
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