一次RAC例項驅逐詳細分析及解決方案

yingyifeng306發表於2018-06-06

一 問題說明

接同事郵件，緊急處理客戶extent RAC節點例項驅逐故障分析。我們根據客戶提供的日誌，結合具體的環境及詳細的trace檔案進行分析，在儘可能的情況下，給出故障結論，由於故障發生時候，缺失相關的核心trace檔案等，所以我們根據現有的日誌，結合該環境本身的一些技術指標，給出一個可預判的故障結論。

二 故障處理的關鍵時間點

時間點

故障處理關鍵點

03-17 15:28:00

接到郵件，開始具體分析故障日誌

03-17 16:00:00

結合現有的日誌，給出故障初步結論

03-17 16:20:00

郵件回覆技術細節內容

03-17 17:00:00

詳細提交技術分析細節


三 故障具體日誌分析

3.1 故障時間一節點叢集告警日誌分析

2017-03-04 01:28:01.282:

[ctssd(265396)]CRS-2409:The clock on host ggudb-kl1p4-14 is not synchronous with the mean cluster time. No action has been taken as the Cluster Time Synchronization Service is running in observer mode.

2017-03-04 01:58:01.915:

[ctssd(265396)]CRS-2409:The clock on host ggudb-kl1p4-14 is not synchronous with the mean cluster time. No action has been taken as the Cluster Time Synchronization Service is running in observer mode.

2017-03-04 02:02:43.306:

[/u01/11.2.0/grid/bin/oraagent.bin(267603)]CRS-5011:Check of resource "oltp" failed: details at "(:CLSN00007:)" in "/u01/11.2.0/grid/log/ggudb-kl1p4-14/agent/crsd/oraagent_oracle/oraagent_oracle.log"

2017-03-04 02:03:17.323:

[/u01/11.2.0/grid/bin/oraagent.bin(267603)]CRS-5818:Aborted command 'check' for resource 'ora.oltp.mynode1.svc'. Details at (:CRSAGF00113:) {0:9:19} in /u01/11.2.0/grid/log/ggudb-kl1p4-14/agent/crsd/oraagent_oracle/oraagent_oracle.log.

2017-03-04 02:05:16.514:

[/u01/11.2.0/grid/bin/oraagent.bin(267603)]CRS-5818:Aborted command 'check' for resource 'ora.oltp.mynode1.svc'. Details at (:CRSAGF00113:) {0:9:19} in /u01/11.2.0/grid/log/ggudb-kl1p4-14/agent/crsd/oraagent_oracle/oraagent_oracle.log.

2017-03-04 02:28:02.558:

[ctssd(265396)]CRS-2409:The clock on host ggudb-kl1p4-14 is not synchronous with the mean cluster time. No action has been taken as the Cluster Time Synchronization Service is running in observer mode.

2017-03-04 02:58:05.193:

從一節點叢集告警日誌看，在故障時間節點（2017-03-04 02:02:43）資料庫CRS程式接收到本節點資料庫例項及資料庫服務CRASH的資訊。從這裡我們可以分析到，在該故障時間段，叢集本身並沒有crash只是1節點例項被驅逐。

3.2 故障時間二節點叢集告警日誌分析

[crsd(243374)]CRS-2772:Server 'ggudb-kl1p4-14' has been assigned to pool 'ora.oltp_mynode1'.

2017-03-04 02:02:47.120:

[crsd(243374)]CRS-2765:Resource 'ora.oltp.db' has failed on server 'ggudb-kl1p4-14'.

2017-03-04 02:05:34.367:

[crsd(243374)]CRS-2765:Resource 'ora.oltp.mynode1.svc' has failed on server 'ggudb-kl1p4-14'.

2017-03-04 02:05:34.367:

[crsd(243374)]CRS-2771:Maximum restart attempts reached for resource 'ora.oltp.mynode1.svc'; will not restart.

2017-03-05 00:12:21.690:

可以看到在同一時間，二節點也發出了一節點例項crash的資訊

3.3 故障時間一節點rdbms日誌

IPC Send timeout detected. Sender: ospid 267775 [oracle@ggudb-kl1p4-14 (PING)]

Receiver: inst 2 binc 429635545 ospid 244165

Sat Mar 04 02:02:34 2017

minact-scn master exiting with err:12751

Sat Mar 04 02:02:41 2017

IPC Send timeout detected. Sender: ospid 267880 [oracle@ggudb-kl1p4-14 (LMD0)]

Receiver: inst 2 binc 429635551 ospid 244173

IPC Send timeout to 2.0 inc 4 for msg type 65521 from opid 12

Sat Mar 04 02:02:42 2017

Suppressed nested communications reconfiguration: instance_number 2

Detected an inconsistent instance membership by instance 2

Sat Mar 04 02:02:42 2017

Received an instance abort message from instance 2

Received an instance abort message from instance 2

Please check instance 2 alert and LMON trace files for detail.

Please check instance 2 alert and LMON trace files for detail.

LMS0 (ospid: 267888): terminating the instance due to error 481

Sat Mar 04 02:02:42 2017

System state dump requested by (instance=1, osid=267888 (LMS0)), summary=[abnormal instance termination].

System State dumped to trace file /u01/app/oracle/diag/rdbms/oltp/oltp1/trace/oltp1_diag_267757_20170304020242.trc

Sat Mar 04 02:02:47 2017

ORA-1092 : opitsk aborting process

Sat Mar 04 02:02:47 2017

License high water mark = 438

Instance terminated by LMS0, pid = 267888

USER (ospid: 715453): terminating the instance

Instance terminated by USER, pid = 715453

Sun Mar 05 22:51:42 2017

可以看到，在故障發生時候，一節點因為接收到來自二節點的例項驅逐資訊（Received an instance abort message from instance 2）進而導致例項crash

3.4 故障時間二節點rdbms日誌

Sat Mar 04 02:00:33 2017

IPC Send timeout detected. Receiver ospid 244324 [

Sat Mar 04 02:00:33 2017

Errors in file /u01/app/oracle/diag/rdbms/oltp/oltp2/trace/oltp2_lck0_244324.trc:

Sat Mar 04 02:02:10 2017

##########發現節點無法和一節點LMD程式進行通訊###############

LMD0 (ospid: 244173) has detected no messaging activity from instance 1

LMD0 (ospid: 244173) issues an IMR to resolve the situation

Please check LMD0 trace file for more detail.

Sat Mar 04 02:02:10 2017

########重置一節點通訊|################

Communications reconfiguration: instance_number 1

Sat Mar 04 02:02:41 2017

IPC Send timeout detected. Receiver ospid 244173 [

Sat Mar 04 02:02:41 2017

Errors in file /u01/app/oracle/diag/rdbms/oltp/oltp2/trace/oltp2_lmd0_244173.trc:

Sat Mar 04 02:02:42 2017

##############對一節點發起驅逐######################

Detected an inconsistent instance membership by instance 2

Evicting instance 1 from cluster

Waiting for instances to leave: 1

Dumping diagnostic data in directory=[cdmp_20170304020242], requested by (instance=1, osid=267888 (LMS0)), summary=[abnormal instance termination].

Reconfiguration started (old inc 4, new inc 8)

List of instances:

 2 (myinst: 2)

 Global Resource Directory frozen

可以詳細看到，在2節點的rdbms日誌中，因LMD程式通訊超時，2節點向一節點發起了驅逐，簡單來說，在故障時間中，一節點的LMD程式因某些原因，導致無法與2節點進行進行通訊，為了保證資料一致性，叢集在資料庫層面發起了驅逐（Instance Evicting）

3.5 一節點叢集心跳日誌

2017-03-04 02:02:37.347: [    CSSD][3417790208]clssnmSendingThread: sent 5 status msgs to all nodes

2017-03-04 02:02:42.349: [    CSSD][3417790208]clssnmSendingThread: sending status msg to all nodes

2017-03-04 02:02:42.349: [    CSSD][3417790208]clssnmSendingThread: sent 5 status msgs to all nodes

2017-03-04 02:02:42.694: [    CSSD][3646260992]clssgmDeadProc: proc 0x7f42d030a6a0

2017-03-04 02:02:42.694: [    CSSD][3646260992]clssgmDestroyProc: cleaning up proc(0x7f42d030a6a0) con(0x47f7) skgpid 267966 ospid 267966 with 0 clients, refcount 0

2017-03-04 02:02:42.694: [    CSSD][3646260992]clssgmDiscEndpcl: gipcDestroy 0x47f7

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmDeadProc: proc 0x7f42d02f21f0

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmFenceClient: fencing client(0x7f42d02e77f0), member(3) in group(GR+GCR1), death fence(1), SAGE fence(0)

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmUnreferenceMember: global grock GR+GCR1 member 3 refcount is 1

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmFenceProcessDeath: client (0x7f42d02e77f0) pid 267914 undead

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmQueueFenceForCheck: (0x7f42d02f5730) Death check for object type 3, pid 267914

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmDiscEndpcl: gipcDestroy 0x471d

2017-03-04 02:02:42.703: [    CSSD][2348807936]clssgmFenceCompletion: (0x7f42d02f5730) process death fence completed for process 267914, object type 3

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmDestroyProc: cleaning up proc(0x7f42d02f21f0) con(0x46ee) skgpid 267914 ospid 267914 with 0 clients, refcount 0

2017-03-04 02:02:42.703: [    CSSD][3646260992]clssgmDiscEndpcl: gipcDestroy 0x46ee

2017-03-04 02:02:42.703: [    CSSD][2348807936]clssgmTermMember: Terminating member 3 (0x7f42d02f29e0) in grock GR+GCR1

2017-03-04 02:02:42.703: [    CSSD][2348807936]clssgmQueueGrockEvent: groupName(GR+GCR1) count(4) master(0) event(2), incarn 6, mbrc 4, to member 1, events 0x280, state 0x0

2017-03-04 02:02:42.703: [    CSSD][2348807936]clssgmUnreferenceMember: global grock GR+GCR1 member 3 refcount is 0

2017-03-04 02:02:42.703: [    CSSD][2348807936]clssgmAllocateRPCIndex: allocated rpc 121 (0x7f42d96d2f78)

2017-03-04 02:02:42.703: [    CSSD][2348807936]clssgmRPC: rpc 0x7f42d96d2f78 (RPC#121) tag(79002a) sent to node 2

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmDeadProc: proc 0x7f42d039c680

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmFenceClient: fencing client(0x7f42d0399e40), member(0) in group(DG_LOCAL_DATA), death fence(1), SAGE fence(0)

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmUnreferenceMember: local grock DG_LOCAL_DATA member 0 refcount is 23

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmFenceProcessDeath: client (0x7f42d0399e40) pid 267964 undead

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmQueueFenceForCheck: (0x7f42d0394610) Death check for object type 3, pid 267964

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmFenceClient: fencing client(0x7f42d0391770), member(0) in group(DG_LOCAL_REDO), death fence(1), SAGE fence(0)

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmUnreferenceMember: local grock DG_LOCAL_REDO member 0 refcount is 2

2017-03-04 02:02:42.704: [    CSSD][3646260992]clssgmFenceProcessDeath: client (0x7f42d0391770) pid 267964 undead

可以看到CSS進城已經檢測到部分death進城透過分析資料庫告警日誌可以獲得這部分作業系統程式對應的oracle程式:


從上述的日誌分析看，故障時候，LMSx相關的程式因某些原因導致僵死，進而導致通訊失敗，從而二節點對一節點發起了例項層的crash



四 故障總結

4.1 故障結論分析

結合第三章節的故障分析，從現有的日誌上看，LMS程式僵死超時是導致資料庫被驅逐的最主要原因。而在RAC例項間主要的通訊程式有LMON, LMD, LMSx等程式。正常來說，當一個訊息被髮送給其它例項之後，傳送者期望接收者會回覆一個確認訊息，但是如果這個確認訊息沒有在指定的時間內收到（預設300秒），傳送者就會認為訊息沒有達到接收者，於是會出現“IPC Send timeout”問題。而導致上述這些程式僵死或者超時的原因不外乎以下幾種：

?  網路問題造成丟包或者通訊異常。

?  由於主機資源(CPU、記憶體、I/O等）問題造成這些程式無法被排程或者這些程式無響應。

?  Oracle Bug.
從目前來看，ORACLE 的BUG 可能性也存在，但是相對可能性較小，之所以說bug可能存在，原因在於資料庫並沒有安裝任何PSU：

There are no Interim patches installed in this Oracle Home.

Rac system comprising of multiple nodes

  Local node = ggudb-kl1p4-14

  Remote node = xhmdb-kl1p4-24

--------------------------------------------------------------------------------

OPatch succeeded.

而主機資源方面，從目前的情況看，原則上這個時間段系統並不會特別卡，除非存在夜間批處理，或者備份等定時任務在大量開銷主機資源（CPU 記憶體 IO）

最終我們來說網路問題，這也是可能性最大的，之所以這麼說，因為在故障時間段，大量的IPC Send timeout detected. 這也在一定程度上說明故障時候心跳之間的延遲還是比較厲害。

上述的三種情況，BUG這塊相對確定並且排除是最方便的，而資源不足和網路延遲等，需要更進一步的日誌，比較遺憾，在諮詢客戶後，客戶告知在故障時間段的時候並沒有部署OSwatch ，這就導致故障時間段的作業系統trace相對缺失。

4.2 解決方案

從上述4.1節的分析，我們給出如下建議：

1.       開啟OSwatch ，我們在這裡稍微在說明一下：

開啟OSwatch的自啟動

雙節點部署如下資訊：

linux：/etc/rc.local下部署如下資訊：（檔案呼叫路徑自行修改）

##########################

/bin/sh /osw/autostartosw.sh

#######################################################################

編輯如下檔案（檔案呼叫路徑自行修改）

cd /osw/oswbb

/usr/bin/nohup sh startOSWbb.sh 10 48 gzip /osw/archive&

同時開啟private監控：

# vi private.net（新增如下資訊，後面跟別名）

traceroute -r -F hisrac01-priv

traceroute -r -F hisrac02-priv

# ll private.net

-rwx------ 1 root root 94 May 25 16:16 private.net 確保可以執行，有執行許可權

# ./private.net（手工嘗試執行）

traceroute to hisrac01-priv (10.10.10.31), 30 hops max, 60 byte packets

1 hisrac01-priv (10.10.10.31) 0.111 ms 0.021 ms 0.016 ms

traceroute to hisrac02-priv (10.10.10.32), 30 hops max, 60 byte packets

1 hisrac02-priv (10.10.10.32) 0.215 ms 0.200 ms 0.189 ms

手工開啟 nohup sh startOSWbb.sh 10 48 gzip /osw/archive&

2.  作為extent RAC 儘量建立單獨的service確保多個應用各自連線自己的資料庫例項，減小心跳壓力，如果採用普通normal儲存配置，建議當前節點連線當前節點對應的儲存。較少裸光纖壓力。

3.  從目前來看，資料庫及叢集未安裝任何PSU，作為生產環境，這是絕對不允許的，建議可以針對最新的PSU進行patch



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原部落格地址：http://blog.itpub.net/23732248/
原作者：應以峰 (frank-ying)
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