RAC interconnect failure
We have set up a RAC DB and we are trying to understand the effect of interconnect failure. Our understanding is that when interconnect fails, the RAC will use the information in voting disk to decide which node will survive and which node will be shut down. We want to make sure that is what is going to happen. Interconnect failure will not result in both node being shutdown, correct?
Please point us to the right oracle doc about this isssue, if one exists. We were not able to find firm answer on the docs we have read so far.
Thanks.
Is it true that when a interconnect failure occurs in a two node cluster, lowest node number rule? Well, I am not sure this could be true or not. Couple of times its been observed in our two node RAC Databases where each time one node evicted due to couple reasons (one of the reason was the time synchronization between the nodes) and surprisingly another time a node evicted without any valid reason too.
Jaffar
Similar Messages
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Lowest node number rule in 2 nodes RAC when interconnect failure
Is it true that when a interconnect failure occurs in a two node cluster, lowest node number rule? Assume both the nodes can access the voting disk(s).
If true, any documentation or white pager to address more details?
Thanks in advance.
Limin.Is it true that when a interconnect failure occurs in a two node cluster, lowest node number rule? Well, I am not sure this could be true or not. Couple of times its been observed in our two node RAC Databases where each time one node evicted due to couple reasons (one of the reason was the time synchronization between the nodes) and surprisingly another time a node evicted without any valid reason too.
Jaffar -
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. -
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 -
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
------------------------------------------------------------- -
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 and crossover
Let assume that we have only 2 nodes in oracle cluster.
What is better for interconnect:
Crossover or network with switch and why?
Thank you.
ps. we have dispute with 2nd DBA.Hi Alex, all,
sorry, but I find this discussion dangerous, since missleading. Please, let me make it very clear:
If you plan to set up a production system, Oracle will not support crossover cables!
Therefore, regardless of whether or not a crossover cable is technically possible, it has no advantage over a switch. For test systems you may want to use anything that you want. However, please, note that a test system with a crossover cable cannot be a test environment for interconnect failure tests.
The reason is that Oracle has found that a lot of the interconnect failure tests will perform totally differently when using a switch - the network guys on this forum may want to elaborate why. In addition, Oracle has seen issues with crossover cables even under normal circumstances (no physical failure). While those were mostly based on auto speed negotiation of the NICs on both sides when using a crossover cable or other OS settings that need to be optimized, the behaviour was more predictable and stable using a switch.
Concluding, you would need to use a switch on your interconnect.
Thanks,
Markus -
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 -
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 -
Failed to restart the CSSD during the interconnect failure
Hi all,
I run a small ATP on my LAB where i have
- 2x nodes RAC 11.2.0.2 & ASM (my OCR & Voting files are stored on ASM)
- 1 public interface <> eth0
- 1 private interface <> eth1
- 1 SCAN IP defined in the /etc/hosts file (i'm not using DNS or GNS)
The test i run was to shutdown the private interface (eth1) on node 1 and i saw that
1) all cluster services and cluster daemons on node 2 were killed and node 2 was evicted from the cluster by node 1
2) all new connections were redirected to the survived node
3) Oracle OHASD daemon was restarted on node 2 and tried to start the cluster services without success because private network between cluster nodes was down
Up to here everything worked as expected but once i turn on eth1 it took ~ 9 minutes for the CSSD to startup and bring all the components up & running.
The node2 alert logs showes
[ctssd(12949)]CRS-2402:The Cluster Time Synchronization Service aborted on host node2. Details at (:ctss_css_init1:) in /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/ctssd/octssd.log.
2011-04-13 08:09:40.978
[ohasd(5058)]CRS-2765:Resource 'ora.cssd' has failed on server 'node2'.
2011-04-13 08:09:40.985
[/u01/oracle/installed/oracle_cluster-11.2.0.2-1/bin/oraagent.bin(5764)]CRS-5011:Check of resource "+ASM" failed: details at "(:CLSN00006:)" in "/u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/agent/ohasd/oraagent_oracle/oraagent_oracle.log";
2011-04-13 08:09:41.169
[ohasd(5058)]CRS-2765:Resource 'ora.asm' has failed on server 'node2'.
2011-04-13 08:09:50.337
[cssd(13103)]CRS-1713:CSSD daemon is started in clustered mode
2011-04-13 08:10:05.833
[cssd(13103)]CRS-1707:Lease acquisition for node node2 number 2 completed
2011-04-13 08:10:07.119
[cssd(13103)]CRS-1605:CSSD voting file is online: ORCL:CRS_DISK1_2G; details in /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/cssd/ocssd.log.
2011-04-13 08:10:07.121
[cssd(13103)]CRS-1605:CSSD voting file is online: ORCL:CRS_DISK2_2G; details in /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/cssd/ocssd.log.
2011-04-13 08:10:07.143
[cssd(13103)]CRS-1605:CSSD voting file is online: ORCL:CRS_DISK1_2G; details in /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/cssd/ocssd.log.
2011-04-13 08:19:49.386
[/u01/oracle/installed/oracle_cluster-11.2.0.2-1/bin/cssdagent(13091)]CRS-5818:Aborted command 'start for resource: ora.cssd 1 1' for resource 'ora.cssd'. Details at (:CRSAGF00113:) {0:6:7} in /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/agent/ohasd/oracssdagent_root/oracssdagent_root.log.
2011-04-13 08:19:49.387
[cssd(13103)]CRS-1656:The CSS daemon is terminating due to a fatal error; Details at (:CSSSC00012:) in /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/cssd/ocssd.log
2011-04-13 08:19:49.387
[cssd(13103)]CRS-1603:CSSD on node node2 shutdown by user.
2011-04-13 08:19:54.501
[ohasd(5058)]CRS-2765:Resource 'ora.cssdmonitor' has failed on server 'node2'.
2011-04-13 08:19:57.723
[cssd(17068)]CRS-1713:CSSD daemon is started in clustered mode
2011-04-13 08:20:01.177
[ohasd(5058)]CRS-2765:Resource 'ora.diskmon' has failed on server 'node2'.
2011-04-13 08:20:13.167
[cssd(17068)]CRS-1707:Lease acquisition for node node2 number 2 completed pay attention at the timestamp 08:10:07.143 & 08:19:49.386
The error in the oracssdagent_root.log is
2011-04-13 08:09:49.286: [CLSFRAME][3014212592] New Framework state: 2
2011-04-13 08:09:49.286: [CLSFRAME][3014212592] M2M is starting...
2011-04-13 08:09:49.288: [ CRSCOMM][3014212592] Ipc: Starting send thread
2011-04-13 08:09:49.288: [ CRSCOMM][1092061504] Ipc: sendWork thread started.
2011-04-13 08:09:49.289: [ CRSCOMM][1105643840] IpcC: IPC Client thread started listening
2011-04-13 08:09:49.289: [ CRSCOMM][1105643840] IpcC: Received member number of 10
2011-04-13 08:09:49.290: [CLSFRAME][3014212592] New IPC Member:{Relative|Node:0|Process:0|Type:2}:OHASD:node2
2011-04-13 08:09:49.290: [CLSFRAME][3014212592] New process connected to us ID:{Relative|Node:0|Process:0|Type:2} Info:OHASD:node2
2011-04-13 08:09:49.291: [CLSFRAME][3014212592] Tints initialized with nodeId: 0 procId: 10
2011-04-13 08:09:49.291: [CLSFRAME][3014212592] Starting thread model named: MultiThread
2011-04-13 08:09:49.292: [CLSFRAME][3014212592] Starting thread model named: TimerSharedTM
2011-04-13 08:09:49.293: [CLSFRAME][3014212592] New Framework state: 3
2011-04-13 08:09:49.293: [ AGFW][3014212592] Agent Framework started successfully
2011-04-13 08:09:49.293: [ AGFW][1116150080] {0:10:2} Agfw engine module has enabled...
2011-04-13 08:09:49.293: [CLSFRAME][1116150080] {0:10:2} Module Enabling is complete
2011-04-13 08:09:49.293: [CLSFRAME][1116150080] {0:10:2} New Framework state: 6
2011-04-13 08:09:49.294: [CLSFRAME][3014212592] M2M is now powered by a doWork() thread.
2011-04-13 08:09:49.294: [ AGFW][1116150080] {0:10:2} Agent is started with userid: root , expected user: root
2011-04-13 08:09:49.294: [ AGENT][1116150080] {0:10:2} Static Version 11.2.0.2.0
2011-04-13 08:09:49.294: [ AGFW][1116150080] {0:10:2} Agent sending message to PE: AGENT_HANDSHAKE[Proxy] ID 20484:11
2011-04-13 08:09:49.302: [ AGFW][1116150080] {0:10:2} Agent received the message: RESTYPE_ADD[ora.cssd.type] ID 8196:12358
2011-04-13 08:09:49.302: [ AGFW][1116150080] {0:10:2} Added new restype: ora.cssd.type
2011-04-13 08:09:49.303: [ AGFW][1116150080] {0:10:2} Agent sending last reply for: RESTYPE_ADD[ora.cssd.type] ID 8196:12358
2011-04-13 08:09:49.305: [ AGFW][1116150080] {0:10:2} Agent received the message: RESOURCE_ADD[ora.cssd 1 1] ID 4356:12359
2011-04-13 08:09:49.305: [ AGFW][1116150080] {0:10:2} Added new resource: ora.cssd 1 1 to the agfw
2011-04-13 08:09:49.306: [ AGFW][1116150080] {0:10:2} Agent sending last reply for: RESOURCE_ADD[ora.cssd 1 1] ID 4356:12359
2011-04-13 08:09:49.308: [ AGFW][1116150080] {0:6:7} Agent received the message: RESOURCE_START[ora.cssd 1 1] ID 4098:12360
2011-04-13 08:09:49.308: [ AGFW][1116150080] {0:6:7} Preparing START command for: ora.cssd 1 1
2011-04-13 08:09:49.308: [ AGFW][1116150080] {0:6:7} ora.cssd 1 1 state changed from: UNKNOWN to: STARTING
2011-04-13 08:09:49.309: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_cssdstart: Start action called
2011-04-13 08:09:49.309: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_getattr: attr OMON_INITRATE, value 1000
2011-04-13 08:09:49.309: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_getattr: attr OMON_POLLRATE, value 500
2011-04-13 08:09:49.309: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_getattr: attr ORA_OPROCD_MODE, value
2011-04-13 08:09:49.310: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_getattr: attr PROCD_TIMEOUT, value 1000
2011-04-13 08:09:49.310: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_getattr: attr LOGGING_LEVEL, value 1
2011-04-13 08:09:49.310: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_cssdstart: loglevels CSSD=2,GIPCNM=2,GIPCGM=2,GIPCCM=2,CLSF=0,SKGFD=0,GPNP=1,OLR=0
2011-04-13 08:09:49.313: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_cssdstart: START action for resource /u01/oracle/installed/oracle_cluster-11.2.0.2-1/bin/ocssd: SUCCESS
2011-04-13 08:09:49.313: [ora.cssd][1114048832] {0:6:7} [start] clsncssd_waitomon: start waiting
2011-04-13 08:09:49.313: [ CSSCLNT][1098377536]clsssInitNative: Init for agent
2011-04-13 08:09:50.317: [ CSSCLNT][1098377536]clsssInitNative: Init for agent
2011-04-13 08:09:51.319: [ CSSCLNT][1098377536]clsssInitNative: Init for agent
2011-04-13 08:09:51.322: [ CSSCLNT][1098377536]clssnsqueryfatal: css is fatal = 0
2011-04-13 08:09:51.322: [ USRTHRD][1098377536] clsncssd_thrdspawn: spawn OPROCD succ
2011-04-13 08:09:51.322: [ USRTHRD][1098377536] clsncssd_thrdspawn: spawn POLLMSG succ
2011-04-13 08:09:51.323: [ USRTHRD][1099954496] clsnpollmsg_main: starting pollmsg thread
2011-04-13 08:09:51.323: [ USRTHRD][1107745088] clsnproc_main: timeout of procd cannot be 0, now we set to default 1000.
2011-04-13 08:09:51.323: [ USRTHRD][1117727040] clsnwork_main: starting worker thread
2011-04-13 08:09:51.323: [ USRTHRD][1098377536] clsncssd_thrdspawn: spawn WORKER succ
2011-04-13 08:09:51.323: [ USRTHRD][1107745088] clsnproc_main: starting oprocd
2011-04-13 08:09:51.323: [ USRTHRD][1098377536] clsncssd_thrdspawn: spawn KILL succ
2011-04-13 08:10:07.151: [ USRTHRD][1098377536] clsnomon_init: css init done, nodenum 2
2011-04-13 08:10:07.151: [ USRTHRD][1098377536] clsnomon_WaitToRegister: waiting for first reconfiguration and kgzf initialization
2011-04-13 08:19:49.385: [CLSFRAME][3014212592] TM [MultiThread] is changing desired thread # to 3. Current # is 2
2011-04-13 08:19:49.387: [ AGFW][1111947584] {0:6:7} Created alert : (:CRSAGF00113:) : Aborting the command: start for resource: ora.cssd 1 1
2011-04-13 08:19:49.387: [ora.cssd][1111947584] {0:6:7} [start] clsncssd_cssdabort: sending shutdown abort to CSS with new ctx
2011-04-13 08:19:49.387: [ CSSCLNT][1098377536]clsssRecvMsg: wrong type request (0) on 0xc9 ret 0
2011-04-13 08:19:49.387: [ CSSCLNT][1098377536]clssnskgzfdone: RPC failed rc 1
2011-04-13 08:19:49.387: [ USRTHRD][1098377536] clsnomon_WaitToRegister: exadata initialization completed with rc=1
2011-04-13 08:19:49.387: [ USRTHRD][1098377536] clsnomon_init: problems in the CSS to allow OMON registration 2
2011-04-13 08:19:49.387: [ USRTHRD][1098377536] clsnomon_cleanup: to exit status = 2
2011-04-13 08:19:49.387: [ USRTHRD][1098377536] clsnomon_cleanup: failure, sending shutdown immediate to CSS
2011-04-13 08:19:49.387: [ USRTHRD][1098377536] CHECK action is in progress, Rejecting the check action requested by entry point for ora.cssd
2011-04-13 08:19:49.426: [ AGFW][2008402928] Starting the agent: /u01/oracle/installed/oracle_cluster-11.2.0.2-1/log/node2/agent/ohasd/oracssdagent_root/
2011-04-13 08:19:49.426: [ AGENT][2008402928] Agent framework initialized, Process Id = 17013
2011-04-13 08:19:49.426: [ USRTHRD][2008402928] to enter agent main
2011-04-13 08:19:49.426: [ USRTHRD][2008402928] clsscssd_main: New soft limit for stack size is 1572864, hard limit is 4294967295
2011-04-13 08:19:49.434: [ USRTHRD][2008402928] clsncssd_main: setting priority to 4
2011-04-13 08:19:49.434: [ USRTHRD][2008402928] *** Agent Framework Started *** Do you have any idea why it took so long to bring all the components up & running?
Thanks a lot!!
GHi,
there is an internal timer for the clusterware ressources regarding restarting the ressources.
In case of a node eviction or clusterstack reboot the clusterware tries to startup again.
If the issue still persists, CRS will wait for some time to start the stack again. This "restart" try is based on a timer, which is set to 600 seconds (note this is not the ORA_CHECK_TIMEOUT) but the STARTUP_TIMEOUT.
Since a missing interconnect does have some implications (not only on the network but on the whole stack) it is expected, that the cluster does not start so fast automatically (because it still has the first start running.
There is even another "issue" connected to this - Oracle will only try several times (FAILURE_COUNT/FAILURE_THRESHOLD) to restart ressources. If he cannot restart cssd/crsd for several times, OCW will not try to startup automatically, but expects the administrator to solve the error and then startup again.
But actually this does make sense:
We have to give some time for an error to be resolved, before we start automatically. It does not matter if the restart of the node is delayed by this, because
=> If the error is fixed automatically, it will normally be fixed after a cluster/node reboot and hence cluster will come up
=> If the error is not fixed automatically, but manually, it can be expected that the administrator tells clusterware the issue is resolved. He does that by simply starting the stack (crsctl start crs)
=> If the error is fixed automaticall, but fixing took a while (lets say 15 minutes), it does not really matter if clusterware needs 10 more minutes to come up.
So what you see is expected, and wanted.
It would cost way too much to monitor all ressources regarding cluster problems and trigger a startup....
Sebastian -
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). -
If RAC interconnect can handle this?
Could anybody tell me if RAC cluster still persists if we take if out of network? I mean to ask if nodes will still be able to talk to each other via interconnect? Does CRS handle all this?
Thanks to all in advance
gtcolHello,
Consider a scenario, Two node rac cluster with each node having one Public, Private and Virtual IP configured.
f your Public interface is down on either one of the nodes then CRS decides to move VIP to another node of the cluster and listener configured on that node would go offline state, also some of the higly available services which are running on that node using it as Preferred node would move to another node from that node . However if your Private interconnect fails due to some problem on either of the nodes, then NODE EVICTION process is started by CRS in order to avoid Split Brain Situation, the CRS evicts that node from the cluster and reboots that node.
In case of public network failure between all the nodes, all the services would go offline.
Lalit Verma
http://sites.google.com/site/racinsights1 -
Hai,
I need clarification in oracle 9i rac internetconnect. Recently we have done installation of oracle 9i rac (9.2.0.4) on aix 5.3 with hacmp cluster for 2 nodes. We are not able to mount the second instance of the database after starting the first instance.
The problem was solved after adding cluster_interconnect parameter in the init.ora file. In all other servers, it is not given and oracle is selecting the interconnect automatically. For this new server alone this problem. I want to know from whether oracle is taking this interconnect if we dont mention the cluster_interconnect paramter. Even i have verified /etc/hosts file and entries are available in it. Requeting your help in this regard.Where the IP information is stored and managed from depends on your implementation such as are you using a third party clusterware. If you are using Oracle clusterware its stored in the OCR.
You can check this using the following query...
SELECT * FROM GV$CLUSTER_INTERCONNECTS;
The source column will tell you where the interconnect information was obtained from.
BTW, if you are using the CLUSTER_INTERCONNECTS parameter you may loose some of the HA features here is something from the 10gR2 documentation..
" Failover and Failback and CLUSTER_INTERCONNECTS
Some operating systems support run-time failover and failback. However, if you use the CLUSTER_INTERCONNECTS initialization parameter, then failover and failback are disabled."
Question, have you tried other options such as NIC pairing and bonding to have dual interconnects instead of using the CLUSTER_INTERCONNECTS parameter.
Please check Metalink Note # 298891.1 talks about configuring NIC bonding on Linux there are similar options for other operating systems.
answered by Murali Vallath refer the link: this will be very useful to you.http://kr.forums.oracle.com/forums/thread.jspa?threadID=625931
hope, this will helps you. -
Hi guys,
I've this doubt since I'm using Oracle RAC... Oracle recommends the use of a dedicated swith to the RAC servers communication. We are talking about using a dedicated switch to the heartbeat mechanism or to allowing one RAC node to read data blocks from another RAC node's cache via the Interconnect?
Thanks.
A.krishan Jaglan wrote:
Hi User8897201,
as far as i know, Interconnect and heartbeat goes over same link( there is no way to separate them out). If you have Big switch and/Or don't want a physical switch just of RAC , you can ask your Network Administrator to create VLAN for (Interconnect ) - Its same as dedicated switch as RAC traffic will no interrupted by flooded network by anything else.
Key is Network must be dedicated for Interconnect( Non Shared Network), how you achieve doesn't mattter ( either dedicated switch or VLAN just for Interconnect).Again, I have seen a switch that uses a VLAN get saturated to the point that one or more nodes from a cluster rebooted. A switch - even a director-class switch only has so much bandwidth - which if not dedicated to cluster interconnect can still get overwhelmed causing node evictions. Been there, done that, switched to dedicated and then got the T-Shirt.
>
Hope it helps you.
Thanks
krishan Jaglan -
Oracle RAC interconnect performance by GRIDControl
Hi All,
We have Oracle 10g Rac and we manage database through Grid control.
We are not able to see <Performance> and <Interconnects> tabs in rac cluster page , do you guys know why?
logged into sysman--> at right corner <targets> at left side I could see database list , I selected Rac database name and clicked --> at the top left most corner I see a link like below, so if I click on this hyper link (DBname) it is taking me to cluster page, here it is not able to enable two tabed pans <Performance> and <Interconnects> can anyone please help me how to check this information in Grid Control
Cluster: DBNAME >
Thanks in advanceFirst click on the target type Cluster Database, that will take you to overall Cluster Database : <your cluster database name> page. There on the top of the page, left side you will see a hyperlink with name Cluster: <cluster name>, click on this cluster name hyperlink that will take you to the Cluster page where interconnect tabs are enabled.
-Harish Kumar Kalra
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