Shulou(Shulou.com)05/31 Report--

This article mainly introduces how DM7 uses bare equipment to build DMRAC, which is very detailed and has a certain reference value. Interested friends must read it!

I. operating environment

Host IP address (external service) IP address (internal communication) instance name operating system

Dmrac1 10.18.13.165 10.10.10.165 rac0 Redhat 6.7dmrac2 10.18.13.166 10.10.10.166 rac1 Redhat 6.7

Shared storage

/ dev/sdb1 / dev/raw/raw1 dcr disk 2G/dev/sdb2 / dev/raw/raw2 voting disk 2G/dev/sdb3 / dev/raw/raw3 data disk1 2G/dev/sdb4 / dev/raw/raw4 data disk2 2G/dev/sdb1 / dev/raw/raw5 data disk3 2G/dev/sdb2 / dev/raw/raw6 data disk4 2G/dev/sdb3 / dev/raw/raw7 log disk1 2G/dev/sdb4 / dev/raw/raw8 log disk2 2G/dev/sdb1 / dev/raw/raw9 log disk3 2G/dev/sdb2 / dev/raw/raw10 log disk4 2G/dev/sdb3 / dev/raw/raw11 log disk5 2G/dev/sdb4 / dev/raw/raw12 log disk6 2G

II. Operating system configuration

1. Turn off the firewall and SELINUX

[root@cs ~] # service iptables stopiptables: Setting chains to policy ACCEPT: nat mangle filter [OK] iptables: Flushing firewall rules: [OK] iptables: Unloading modules: [OK] [root@cs ~] # chkconfig iptables off [root@cs ~] # setenforce 0 [root@cs ~] # sed-is: ^ SELINUX =. * $: SELINUX=disabled:g / etc/selinux/config [root@cs] # service iptables stopiptables: Setting chains to policy ACCEPT: nat mangle filter [OK] iptables: Flushing firewall rules: [OK] iptables: Unloading modules: [OK] [root@cs ~] # chkconfig iptables off [root@cs ~] # setenforce 0 [root@cs ~] # sed-is: ^ SELINUX =. * $: SELINUX=disabled:g / etc/selinux/config

2. Modify the host name

[root@cs ~] # hostname dm1 [root@cs ~] # sed-I s: ^ hostname =. * $: HOSTNAME=dm1:g / etc/sysconfig/network [root@cs ~] # hostname dm2 [root@cs ~] # sed-I s: ^ hostname =. * $: HOSTNAME=dm2:g / etc/sysconfig/network3, Modify hosts file [root@cs ~] # echo "> 10.18.13.165 dm1 > 10.18.13.166 dm2" > > / etc/hosts [root@cs ~] # [root@cs ~] # echo "> 10.18.13.165 dm1 > 10.18.13.166 dm2" > > / etc/hosts [root@cs ~] #

Third, install Dameng software

For more information on installation operation, please see installing Dameng database DM7 in Oracle Linux 7.1for more information.

4. Bind UDEV

[root@dm1 rules.d] # vi 99dmmurf devices.rulesAction = "add", KERNEL== "sdb1", RUN+= "/ bin/raw / dev/raw/raw1% N" ACTION== "add", KERNEL== "sdb2", RUN+= "/ bin/raw / dev/raw/raw2% N" ACTION== "add", KERNEL== "sdb3", RUN+= "/ bin/raw / dev/raw/raw3% N" ACTION== "add", KERNEL== "sdb4", RUN+= "/ bin/raw / dev/raw/raw4% N" ACTION== "add", KERNEL== "sdc1" RUN+= "/ bin/raw / dev/raw/raw5% N" ACTION== "add", KERNEL== "sdc2", RUN+= "/ bin/raw / dev/raw/raw6% N" ACTION== "add", KERNEL== "sdc3", RUN+= "/ bin/raw / dev/raw/raw7% N" ACTION== "add", KERNEL== "sdc4", RUN+= "/ bin/raw / dev/raw/raw8% N" ACTION== "add", KERNEL== "sdd1", RUN+= "/ bin/raw / dev/raw/raw9% N" ACTION== "add", KERNEL== "sdd2" RUN+= "/ bin/raw / dev/raw/raw10% N" ACTION== "add", KERNEL== "sdd3", RUN+= "/ bin/raw / dev/raw/raw11% N" ACTION== "add", KERNEL== "sdd4", RUN+= "/ bin/raw / dev/raw/raw12% N" ACTION== "add", KERNEL== "raw [1-12]", OWNER= "dmdba", GROUP= "dinstall" MODE= "660th" [root@dm1 rules.d] # start_udevStarting udev: [OK] [root@dm1 rules.d] # ls-lrt / dev/raw/total 0crwMurray RW dmdba dinstall-1 root disk 162,0 May 7 16:28 rawctlcrw-rw---- 1 dmdba dinstall 162,9 May 7 16:28 raw9crw-rw---- 1 dmdba dinstall 162,12 May 7 16:28 raw12crw-rw---- 1 dmdba dinstall 162,11 May 7 16:28 raw11crw-rw---- 1 dmdba dinstall 162, 10 May 7 16:28 raw10crw-rw---- 1 dmdba dinstall 162, 6 May 7 16:28 raw6crw-rw---- 1 dmdba dinstall 162, 1 May 7 16:28 raw1crw-rw---- 1 dmdba dinstall 162, 7 May 7 16:28 raw7crw-rw---- 1 dmdba dinstall 162, 8 May 7 16:28 raw8crw-rw---- 1 dmdba dinstall 162, 5 May 7 16:28 raw5crw-rw---- 1 dmdba dinstall 162, 2 May 7 16:28 raw2crw-rw---- 1 dmdba dinstall 162 3 May 7 16:28 raw3crw-rw---- 1 dmdba dinstall 162,4 May 7 16:28 raw4 [root@dm2 /] # cd / etc/udev/rules.d/ [root@dm2 rules.d] # vi 99m Meridian devices.rulesAction = "add", KERNEL== "sdb1", RUN+= "/ bin/raw / dev/raw/raw1% N" ACTION== "add", KERNEL== "sdb2", RUN+= "/ bin/raw / dev/raw/raw2% N" ACTION== "add", KERNEL== "sdb3" RUN+= "/ bin/raw / dev/raw/raw3% N" ACTION== "add", KERNEL== "sdb4", RUN+= "/ bin/raw / dev/raw/raw4% N" ACTION== "add", KERNEL== "sdc1", RUN+= "/ bin/raw / dev/raw/raw5% N" ACTION== "add", KERNEL== "sdc2", RUN+= "/ bin/raw / dev/raw/raw6% N" ACTION== "add", KERNEL== "sdc3", RUN+= "/ bin/raw / dev/raw/raw7% N" ACTION== "add", KERNEL== "sdc4" RUN+= "/ bin/raw / dev/raw/raw8% N" ACTION== "add", KERNEL== "sdd1", RUN+= "/ bin/raw / dev/raw/raw9% N" ACTION== "add", KERNEL== "sdd2", RUN+= "/ bin/raw / dev/raw/raw10% N" ACTION== "add", KERNEL== "sdd3", RUN+= "/ bin/raw / dev/raw/raw11% N" ACTION== "add", KERNEL== "sdd4", RUN+= "/ bin/raw / dev/raw/raw12% N" ACTION== "add", KERNEL== "raw [1-12]" OWNER= "dmdba", GROUP= "dinstall", MODE= "660" [root@dm2 rules.d] # start_udevStarting udev: [OK] [root@dm2 rules.d] # ls-lrt / dev/raw/total 0crwMurray-1 root disk, 0 May 7 16:28 rawctlcrw-rw---- 1 dmdba dinstall 162,9 May 7 16:28 raw9crw-rw---- 1 dmdba dinstall 162,12 May 7 16:28 raw12crw-rw---- 1 dmdba dinstall 162 11 May 7 16:28 raw11crw-rw---- 1 dmdba dinstall 162, 10 May 7 16:28 raw10crw-rw---- 1 dmdba dinstall 162, 6 May 7 16:28 raw6crw-rw---- 1 dmdba dinstall 162, 1 May 7 16:28 raw1crw-rw---- 1 dmdba dinstall 162, 7 May 7 16:28 raw7crw-rw---- 1 dmdba dinstall 162, 8 May 7 16:28 raw8crw-rw---- 1 dmdba dinstall 162, 5 May 7 16:28 raw5crw-rw---- 1 dmdba dinstall 162 2 May 7 16:28 raw2crw-rw---- 1 dmdba dinstall 162, 3 May 7 16:28 raw3crw-rw---- 1 dmdba dinstall 162, 4 May 7 16:28 raw4

You can view the size of bare devices by using the blockdev-- getsize64 / dev/raw/raw1 command

[root@dm1 rules.d] # blockdev-getsize64 / dev/raw/raw12154991104 [root@dm2] # blockdev-getsize64 / dev/raw/raw12154991104

6. Configure dmdcr_cfg.ini file

Create the configuration file dmdcr_cfg.ini under the / dm7/data directory of the 2 nodes, using only bare devices, no ASM file system, no configuration ASM information, only CSS/DB information. Add the following to the file:

[dmdba@dm1 dm7] $mkdir data [dmdba@dm1 dm7] $cd data [dmdba@dm1 data] $vi dmdcr_cfg.iniDCR_N_GRP = 2DCR_VTD_PATH = / dev/raw/raw2DCR_OGUID = 63635 [GRP] DCR_GRP_TYPE = CSSDCR_GRP_NAME = 2DCR_GRP_DSKCHK_CNT = 60 [GRP_CSS] DCR_EP_NAME = CSS0DCR_EP_HOST = 10.10.10.165DCR_EP_PORT = 9541 [GRP_CSS ] DCR_EP_NAME = CSS1DCR_EP_HOST = 10.10.10.166DCR_EP_PORT = 9542 [GRP] DCR_GRP_TYPE = DBDCR_GRP_NAME = GRP_RACDCR_GRP_N_EP = 2DCR_GRP_DSKCHK_CNT = 60 [GRP_RAC] DCR_EP_NAME = RAC0DCR_EP_SEQNO = 0DCR_EP_PORT = 5236DCR_CHECK_PORT = 9741 [GRP_RAC] DCR_EP_NAME = RAC1DCR_EP_SEQNO = 1DCR_EP_PORT = 5236DCR_CHECK_PORT = 9742 [dmdba@dm2 dm7] $mkdir data [dmdba@dm2 dm7] $cd data [dmdba@dm2 data] $vi dmdcr_cfg.iniDCR_N_GRP = 2DCR_VTD_PATH = / dev/raw/raw2DCR_OGUID = 63635 [GRP] DCR_GRP_TYPE = CSSDCR_GRP_NAME = 2DCR_GRP_DSKCHK_CNT = 60 [GRP_CSS] DCR_EP_NAME = CSS0DCR_EP_HOST = 10.10.10.165DCR_EP_PORT = 9541 [GRP_CSS ] DCR_EP_NAME = CSS1DCR_EP_HOST = 10.10.10.166DCR_EP_PORT = 9542 [GRP] DCR_GRP_TYPE = DBDCR_GRP_NAME = GRP_RACDCR_GRP_N_EP = 2DCR_GRP_DSKCHK_CNT = 60 [GRP_RAC] DCR_EP_NAME = RAC0DCR_EP_SEQNO = 0DCR_EP_PORT = 5236DCR_CHECK_PORT = 9741 [GRP_RAC] DCR_EP_NAME = RAC1DCR_EP_SEQNO = 1DCR_EP_PORT = 5236DCR_CHECK_PORT = 9742

Initialization using the DMASMCMD tool (executed by any node)

[dmdba@dm1 ~] $dmasmcmdDMASMCMD V7.1.6.46-Build (2018.02.08-89107) ENTASM > create dcrdisk'/ dev/raw/raw1' 'dcr'the ASM initialize dcrdisk / dev/raw/raw1 to name DMASMdcrUsed time: 1.459 (ms) .ASM > create votedisk' / dev/raw/raw2' 'vote'the ASM initialize votedisk / dev/raw/raw2 to name DMASMvoteUsed time: 1.380 (ms) .ASM > init dcrdisk' / dev/raw/raw1' from'/ dm7/data/dmdcr_cfg.ini 'syntax errorasmcmd parse failed ASM > init dcrdisk' / dev/raw/raw1' from'/ dm7/data/dmdcr_cfg.ini' identified by 'dameng123' [Trace] DG 126 allocate 4 extents for file 0xfe000002.Check dcrdisk failed Please check and try againUsed time: 271.543 (ms) .ASM > init dcrdisk'/ dev/raw/raw1' from'/ dm7/data/dmdcr_cfg.ini' identified by 'dameng123' [Trace] DG 126 allocate 4 extents for file 0xfe000002.Used time: 68.745 (ms) .ASM > init votedisk' / dev/raw/raw2' from'/ dm7/data/dmdcr_cfg.ini' [Trace] DG 125 allocate 4 extents for file 0xfd000002.Used time: 33.488 (ms).

8. Prepare the dminit.ini file for operating system configuration and store it in the / dm7/data directory

System_path = / dm7/datadb_name=racmain = / dev/raw/raw3main_size = 128roll = / dev/raw/raw4roll_size = 128system = / dev/raw/raw5system_size = 128ctl_path = / dev/raw/raw6ctl_size = 8dcrashed pathpath raw1dcrankseqno = 0 [rac0] config_path=/dm7/data/rac0_configport_num = 5236mal_host = 10.10.10.165mal_port = 9340log_size = 256log_path = / dev/raw/raw7log_path = / dev/raw/raw8 [rac1] config_path=/dm7/data/rac1_configport_num = 5236mal_host = 10.10.10.166mal_port = 9341log_size = 256log_path = / dev/raw/raw9log_path = / dev/raw/raw10

IX. Prepare dmdcr.ini configuration file

Dmdcr.ini is the input parameter for the dmcss, dmasmsvr, and dmasmtool tools. The current node serial number and DCR disk path are recorded. Create a dmdcr.ini configuration file under the / dm/dmdbms/data directory of the two nodes, with the same dmdcr_path and the same contents of the dmasvrmal.ini file, with dmdcr_seqo of 0 and 1, respectively.

Node 1:

[dmdba@dmrac1 data] $vi dmdcr.iniDMDCR_PATH = / dev/raw/raw1DMDCR_SEQNO = 0#ASMDMDCR_ASM_RESTART_INTERVAL = 0DMDCR_ASM_STARTUP_CMD = / dm7/bin/dmasmsvr dcr_ini=/dm7/data/dmdcr.ini#DBDMDCR_DB_RESTART_INTERVAL = 0DMDCR_DB_STARTUP_CMD = / dm7/bin/dmserver path=/dm7/data/rac0_config/dm.ini dcr_ini=/dm7/data/dmdcr.ini

Node 2:

[dmdba@dmrac2 data] $vi dmdcr.iniDMDCR_PATH = / dev/raw/raw1DMDCR_SEQNO = 1#ASMDMDCR_ASM_RESTART_INTERVAL = 0DMDCR_ASM_STARTUP_CMD = / dm7/bin/dmasmsvr dcr_ini=/dm7/data/dmdcr.ini#DBDMDCR_DB_RESTART_INTERVAL = 0DMDCR_DB_STARTUP_CMD = / dm7/bin/dmserver path=/dm7/data/rac1_config/dm.ini dcr_ini=/dm7/data/dmdcr.ini

Start the DMCSS service program

1. Register for the DMCSS service

Node one:

[root@dm1] # / dm7/script/root/dm_service_installer.sh-t dmcss-I / dm7/data/dmdcr.ini-p rac1Move the service script file (/ dm7/bin/DmCSSServicerac1 to / etc/rc.d/init.d/DmCSSServicerac1) Finished to create the service (DmCSSServicerac1)

Node 2:

[root@dm2] # / dm7/script/root/dm_service_installer.sh-t dmcss-I / dm7/data/dmdcr.ini-p rac2Move the service script file (/ dm7/bin/DmCSSServicerac2 to / etc/rc.d/init.d/DmCSSServicerac2) Finished to create the service (DmCSSServicerac2)

2. Start the DMCSS service

Node one:

[root@dm1 ~] # service DmCSSServicerac1 startStarting DmCSSServicerac1: [OK]

Node 2:

[root@dm2 ~] # service DmCSSServicerac2 startStarting DmCSSServicerac2: [OK]

11. Operating system configuration initializes the DB environment with dminit

Start the dminit tool at any node to initialize the database. After the dminit execution is complete, the configuration files dm.ini and dmmal.ini are generated in the config_path directory (/ dm7/data/rac0_config and / dm7/data/rac1_config).

[dmdba@dm1 data] $dminit control=/dm7/data/dminit.iniinitdb V7.1.6.46-Build (2018.02.08-89107) ENTdb version: 0x7000afile dm.key not found Use default license will expire in 14 day (s) on 2020-05-21 log file path: / dev/raw/raw7 log file path: / dev/raw/raw8 log file path: / dev/raw/raw9 log file path: / dev/raw/raw10FILE "/ dev/raw/raw5" has already existedFILE "/ dev/raw/raw4" has already existedFILE "/ dev/raw/raw3" has already existedFILE "/ dev/raw/raw6" has already existedFILE "/ dev/raw/raw7" has already existedFILE "/ Dev/raw/raw8 "has already existedFILE" / dev/raw/raw9 "has already existedFILE" / dev/raw/raw10 "has already existedFile" / dev/raw/raw5 "has already existed Whether overwrite (yport0): yFile "/ dev/raw/raw4" has already existed,whether overwrite (ystop 0): yFile "/ dev/raw/raw3" has already existed,whether overwrite (ystop 0): yFile "/ dev/raw/raw6" has already existed,whether overwrite (ystop 0): yFile "/ dev/raw/raw7" has already existed,whether overwrite (ystop 0): yFile "/ dev/raw/raw8" has already existed,whether overwrite (yAssociation 1 dev/raw/raw9 0): yFile "/ dev/raw/raw9" has already existed,whether overwrite (yzone, 1ap0): yFile "/ dev/raw/raw10" has already existed,whether overwrite (yapo, 1ap0): ywrite to dir [/ dm7/data/rac]. Create dm database success. 2020-05-07 16:41:52

Copy the configuration file for Node 1 to Node 2:

[dmdba@dm1 data] $scp-r rac1_config 10.18.13.166: `pwd`the authenticity of host '10.18.13.166 (10.18.13.166)' can't be established.RSA key fingerprint is 89:fc:3e:e3:2d:27:94:07:0e:6b:fc:c5:e8:89:44:1f.Are you sure you want to continue connecting (yes/no)? YesWarning: Permanently added '10.18.13.166' (RSA) to the list of known hosts.dmdba@10.18.13.166's password:sqllog.ini 100% 479 0.5KB/s 00:00dm.ini 100% 40KB 39.8KB/s 00:00dmmal.ini 100% 204 0.2KB/s 00:00 [dmdba@dm1 data] $

Be sure to copy the rac directory generated in node 1 / dm7/data/ directory to node 2's / dm7/data directory, otherwise the following error will occur when starting the database in node 2, because the rac directory and its files generated when using bare devices are not stored in shared storage so that all cluster nodes can access them.

Starting DmServicerac2: [FAILED] file dm.key not found, use default licenseurs read ini warning, default dm.ctl backup path [/ dm7/data/rac/ctl_bak] does not exist.Read ini error, name:SYSTEM_PATH, value:/dm7/data/racdmserver startup failed, code =-803 [Invalid ini config value]

Copy the rac directory generated in node 1 / dm7/data/ directory to node 2's / dm7/data directory

[dmdba@dm1 data] $scp-r rac 10.18.13.166: `pwd`dmdba @ 10.18.13.166 password:dm_20200507164149_942994.ctl 6144 6.0KB/s 00:00TEMP0.DBF 100% 10MB 10.0MB/s 00:00dm_service.prikey 100% 633 0.6KB/s 00:00

Start the database server

1. Register the DM database service on two nodes:

Node one:

[root@dm1] # / dm7/script/root/dm_service_installer.sh-t dmserver-I / dm7/data/rac0_config/dm.ini-d / dm7/data/dmdcr.ini-p rac1Move the service script file (/ dm7/bin/DmServicerac1 to / etc/rc.d/init.d/DmServicerac1) Finished to create the service (DmServicerac1)

Node 2:

[root@dm2] # / dm7/script/root/dm_service_installer.sh-t dmserver-I / dm7/data/rac1_config/dm.ini-d / dm7/data/dmdcr.ini-p rac2Move the service script file (/ dm7/bin/DmServicerac2 to / etc/rc.d/init.d/DmServicerac2) Finished to create the service (DmServicerac2)

2. Start the database

[root@dm1 ~] # service DmServicerac1 startStarting DmServicerac1: [OK] [root@dm2 ~] # service DmServicerac2 startStarting DmServicerac2: [OK]

The manual startup command is as follows, and the window cannot be closed after manual startup, so

. / dmserver / dm7/data/rac0_config/dm.ini dcr_ini=/dm7/data/dmdcr.ini./dmserver / dm7/data/rac1_config/dm.ini dcr_ini=/dm7/data/dmdcr.ini

XIII. Operating system configuration connection database verification

13.1 configure the service name file

[dmdba@dm1 data] $vi / etc/dm_svc.confrac= (10.18.13.166 rac= 10.18.13.166) SWITCH_TIME= (10000) SWITCH_INTERVAL= (10) TIME_ZONE= (480) LANGUAGE= (en) [dmdba@dm2 rac] $vi / etc/dm_svc.confTIME_ZONE= (480) rac= (10.18.13.165) SWITCH_TIME= (10000) SWITCH_INTERVAL= (10) TIME_ZONE= (480) LANGUAGE= (en)

Connect to the RAC cluster

Node one:

[dmdba@dm1 data] $disql SYSDBA/SYSDBA@racServer [10.18.13.166 mode is normal]: mode is normal, state is openlogin used time: 9.596 (ms) disql V7.1.6.46-Build (2018.02.08-89107) ENTConnected to: DM 7.1.6.46SQL > select instance_name from vastly instantly leading line-1 RAC1used time: 5.020 (ms). Execute id is 2.SQL > select * from v$rac_ep_info LINEID EP_NAME EP_SEQNO EP_GUID EP_TIMESTAMP EP_MODE EP_STATUS 1 RAC0 0 2982624975 2982625916 MASTER OK2 RAC1 1 2983098335 2983098713 SLAVE OKused time: 7.731 (ms). Execute id is 3.

Node 2:

SQL > select instance_name from vantage instancecontrol lineID INSTANCE_NAME--1 RAC1used time: 117.515 (ms). Execute id is 1.SQL > select * from v$rac_ep_info LINEID EP_NAME EP_SEQNO EP_GUID EP_TIMESTAMP EP_MODE EP_STATUS -- 1 RAC0 0 2982624975 2982632228 MASTER OK2 RAC1 1 2983098335 2983 105025 SLAVE OKused time: 4.439 (ms). Execute id is 4.

13.3 Test failure reconnection

[dmdba@dm2 rac] $disql SYSDBA/SYSDBA@racServer [10.18.13.166 RAC1used time 5236]: mode is normal, state is openlogin used time: 6.728 (ms) disql V7.1.6.46-Build (2.08-89107) ENTConnected to: DM 7.1.6.46SQL > select instance_name from vastly instantly leading line-1 RAC1used time: 117.515 (ms). Execute id is 1.SQL > select * from v$rac_ep_info LINEID EP_NAME EP_SEQNO EP_GUID EP_TIMESTAMP EP_MODE EP_STATUS -- 1 RAC0 0 2982624975 2982632228 MASTER OK2 RAC1 1 2983098335 2983 105025 SLAVE OKused time: 4.439 (ms). Execute id is 4.

# the rac1 connected at this time, and our kill process:

[root@dm2] # ps-ef | grep dm.inidmdba 6231 10 17:25 pts/2 00:00:44 / dm7/bin/dmserver / dm7/data/rac1_config/dm.ini DCR_INI=/dm7/data/dmdcr.ini-noconsoleroot 10844 5237 0 19:20 pts/2 00:00:00 grep dm.ini [root@dm2] # kill-9 6231

# in the query, the fault reconnection succeeded:

SQL > select instance_name from vaininstance; [- 70065]: Connection exception, switch the current connection sucessful. [- 70065]: Connection exception, switch the current connection sucessful.Server [10.18.13.165 switch the current connection sucessful 5236]: mode is normal, state is openSQL > select instance_name from venerable instance INSTANCE_NAME--1 RAC0used time: 9.443 (ms). Execute id is 807.SQL > select * from v$rac_ep_info LINEID EP_NAME EP_SEQNO EP_GUID EP_TIMESTAMP EP_MODE EP_STATUS -- 1 RAC0 0 2982624975 2982632568 MASTER OK2 RAC1 1 2983098335 2983 105240 SLAVE ERRORused time: 3.184 (ms). Execute id is 808.

You can see that the instance of the connection has changed from rac1 to rac0

The above is all the contents of the article "how DM7 uses bare devices to build DMRAC". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.