技术标签: oracle log 日志监听文件 【Oracle基础】 数据库 listener-l
在ORACLE数据库中,如果不对监听日志文件(listener.log)进行截断,那么监听日志文件(listener.log)会变得越来越大.
在下面的目录下:
$ORACLE_HOME/network/log/listener_$ORACLE_SID.log
在下面的目录下:
$ORACLE_BASE/diag/tnslsnr/主机名称/listener/trace/listener.log
或者通过 lsnrctl status 也可以查看位置
这里展示的是 xml格式的日志,跟.log并无区别。
或者11g可以通过 adrci 命令
oracle@entel2:[/oracle]$adrci
ADRCI: Release 11.2.0.4.0 - Production on Wed Nov 30 20:56:28 2016
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
ADR base = "/oracle"
adrci> help --help可以看帮助命令。输入help show alert,可以看到show alert的详细用法
HELP [topic]
Available Topics:
CREATE REPORT
ECHO
EXIT
HELP
HOST
IPS
PURGE
RUN
SET BASE
SET BROWSER
SET CONTROL
SET ECHO
SET EDITOR
SET HOMES | HOME | HOMEPATH
SET TERMOUT
SHOW ALERT
SHOW BASE
SHOW CONTROL
SHOW HM_RUN
SHOW HOMES | HOME | HOMEPATH
SHOW INCDIR
SHOW INCIDENT
SHOW PROBLEM
SHOW REPORT
SHOW TRACEFILE
SPOOL
There are other commands intended to be used directly by Oracle, type
"HELP EXTENDED" to see the list
adrci> show alert --显示alert信息
Choose the alert log from the following homes to view:
1: diag/clients/user_oracle/host_880756540_80
2: diag/tnslsnr/procsdb2/listener_cc
3: diag/tnslsnr/entel2/sid_list_listener
4: diag/tnslsnr/entel2/listener_rb
5: diag/tnslsnr/entel2/listener
6: diag/tnslsnr/entel2/listener_cc
7: diag/tnslsnr/procsdb1/listener_rb
8: diag/rdbms/ccdg/ccdg
9: diag/rdbms/rb/rb
10: diag/rdbms/cc/cc
Q: to quit
Please select option: 5 --输入数字,查看对应日志
Output the results to file: /tmp/alert_13187_1397_listener_3.ado
2016-06-27 09:15:45.164000 -04:00
Create Relation ADR_CONTROL
Create Relation ADR_INVALIDATION
Create Relation INC_METER_IMPT_DEF
2016-06-27 09:15:46.444000 -04:00
Create Relation INC_METER_PK_IMPTS
System parameter file is /oracle/product/112/network/admin/listener.ora
Log messages written to /oracle/diag/tnslsnr/entel2/listener/alert/log.xml
Trace information written to /oracle/diag/tnslsnr/entel2/listener/trace/ora_16175_140656975550208.trc
Trace level is currently 0
Started with pid=16175
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.45.7.198)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.123.1)(PORT=1521)))
Listener completed notification to CRS on start
......
......
......
需要对监听日志文件(listener.log)进行定期清理。
1:监听日志文件(listener.log)变得越来越大,占用额外的存储空间
2:监听日志文件(listener.log)变得太大会带来一些问题,查找起来也相当麻烦
3:监听日志文件(listener.log)变得太大,给写入、查看带来的一些性能问题、麻烦
定期对监听日志文件(listener.log)进行清理,另外一种说法叫截断日志文件。
列举一个错误的做法
oracle@entel2:[/oracle]$mv listener.log listener.log.20161201
oracle@entel2:[/oracle]$cp /dev/null listener.log
oracle@entel2:[/oracle]$more listener.log
如上所示,这样截断监听日志(listener.log)后,监听服务进程(tnslsnr)并不会将新的监听信息写入listener.log,而是继续写入listener.log.20161201
1:首先停止监听服务进程(tnslsnr)记录日志。
oracle@entel2:[/oracle]$lsnrctl set log_status off
2:将监听日志文件(listener.log)复制一份,以listener.log.yyyymmdd格式命名
oracle@entel2:[/oracle]$cp listener.log listener.log.20161201
3:将监听日志文件(listener.log)清空。清空文件的方法有很多
oracle@entel2:[/oracle]$echo “” > listener.log
或者
oracle@entel2:[/oracle]$cp /dev/null listener.log
或者
oracle@entel2:[/oracle]$echo /dev/null > listener.log
或者
oracle@entel2:[/oracle]$>listener.log
4:开启监听服务进程(tnslsnr)记录日志
oracle@entel2:[/oracle]$lsnrctl set log_status on
当然也可以移走监听日志文件(listener.log),数据库实例会自动创建一个listener.log文件。
oracle@entel2:[/oracle]$ lsnrctl set log_status off
oracle@entel2:[/oracle]$mv listener.log listener.yyyymmdd
oracle@entel2:[/oracle]$lsnrctl set log_status on
当然这些操作应该通过shell脚本来处理,然后结合crontab作业定期清理、截断监听日志文件。
简单一点的(核心部分)
rq=` date +"%d" `
cp $ORACLE_HOME/network/log/listener.log $ORACLE_BACKUP/network/log/listener_$rq.log
su - oracle -c "lsnrctl set log_status off"
cp /dev/null $ORACLE_HOME/network/log/listener.log
su - oracle -c "lsnrctl set log_status on"
这样的脚本还没有解决一个问题,就是截断的监听日志文件保留多久的问题。比如我只想保留这些截断的监听日志一个月时间,我希望作业自动维护。不需要我去手工操作。有这样一个脚本cls_oracle.sh可以完全做到这个,当然它还会归档、清理其它日志文件,例如告警文件(alert_sid.log)等等。功能非常强大。
#!/bin/bash
#
# Script used to cleanup any Oracle environment.
#
# Cleans: audit_log_dest
# background_dump_dest
# core_dump_dest
# user_dump_dest
#
# Rotates: Alert Logs
# Listener Logs
#
# Scheduling: 00 00 * * * /home/oracle/_cron/cls_oracle/cls_oracle.sh -d 31 > /home/oracle/_cron/cls_oracle/cls_oracle.log 2>
&1
#
# Created By: Tommy Wang 2012-09-10
#
# History:
#
RM="rm -f"
RMDIR="rm -rf"
LS="ls -l"
MV="mv"
TOUCH="touch"
TESTTOUCH="echo touch"
TESTMV="echo mv"
TESTRM=$LS
TESTRMDIR=$LS
SUCCESS=0
FAILURE=1
TEST=0
HOSTNAME=`hostname`
ORAENV="oraenv"
TODAY=`date +%Y%m%d`
ORIGPATH=/usr/local/bin:$PATH
ORIGLD=$LD_LIBRARY_PATH
export PATH=$ORIGPATH
# Usage function.
f_usage(){
echo "Usage: `basename $0` -d DAYS [-a DAYS] [-b DAYS] [-c DAYS] [-n DAYS] [-r DAYS] [-u DAYS] [-t] [-h]"
echo " -d = Mandatory default number of days to keep log files that are not explicitly passed as parameters."
echo " -a = Optional number of days to keep audit logs."
echo " -b = Optional number of days to keep background dumps."
echo " -c = Optional number of days to keep core dumps."
echo " -n = Optional number of days to keep network log files."
echo " -r = Optional number of days to keep clusterware log files."
echo " -u = Optional number of days to keep user dumps."
echo " -h = Optional help mode."
echo " -t = Optional test mode. Does not delete any files."
}
if [ $# -lt 1 ]; then
f_usage
exit $FAILURE
fi
# Function used to check the validity of days.
f_checkdays(){
if [ $1 -lt 1 ]; then
echo "ERROR: Number of days is invalid."
exit $FAILURE
fi
if [ $? -ne 0 ]; then
echo "ERROR: Number of days is invalid."
exit $FAILURE
fi
}
# Function used to cut log files.
f_cutlog(){
# Set name of log file.
LOG_FILE=$1
CUT_FILE=${LOG_FILE}.${TODAY}
FILESIZE=`ls -l $LOG_FILE | awk '{print $5}'`
# Cut the log file if it has not been cut today.
if [ -f $CUT_FILE ]; then
echo "Log Already Cut Today: $CUT_FILE"
elif [ ! -f $LOG_FILE ]; then
echo "Log File Does Not Exist: $LOG_FILE"
elif [ $FILESIZE -eq 0 ]; then
echo "Log File Has Zero Size: $LOG_FILE"
else
# Cut file.
echo "Cutting Log File: $LOG_FILE"
$MV $LOG_FILE $CUT_FILE
$TOUCH $LOG_FILE
fi
}
# Function used to delete log files.
f_deletelog(){
# Set name of log file.
CLEAN_LOG=$1
# Set time limit and confirm it is valid.
CLEAN_DAYS=$2
f_checkdays $CLEAN_DAYS
# Delete old log files if they exist.
find $CLEAN_LOG.[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9] -type f -mtime +$CLEAN_DAYS -exec $RM {} \; 2>/dev/null
}
# Function used to get database parameter values.
f_getparameter(){
if [ -z "$1" ]; then
return
fi
PARAMETER=$1
sqlplus -s /nolog <<EOF | awk -F= "/^a=/ {print \$2}"
set head off pagesize 0 feedback off linesize 200
whenever sqlerror exit 1
conn / as sysdba
select 'a='||value from v\$parameter where name = '$PARAMETER';
EOF
}
# Function to get unique list of directories.
f_getuniq(){
if [ -z "$1" ]; then
return
fi
ARRCNT=0
MATCH=N
x=0
for e in `echo $1`; do
if [ ${#ARRAY[*]} -gt 0 ]; then
# See if the array element is a duplicate.
while [ $x -lt ${#ARRAY[*]} ]; do
if [ "$e" = "${ARRAY[$x]}" ]; then
MATCH=Y
fi
done
fi
if [ "$MATCH" = "N" ]; then
ARRAY[$ARRCNT]=$e
ARRCNT=`expr $ARRCNT+1`
fi
x=`expr $x + 1`
done
echo ${ARRAY[*]}
}
# Parse the command line options.
while getopts a:b:c:d:n:r:u:th OPT; do
case $OPT in
a) ADAYS=$OPTARG
;;
b) BDAYS=$OPTARG
;;
c) CDAYS=$OPTARG
;;
d) DDAYS=$OPTARG
;;
n) NDAYS=$OPTARG
;;
r) RDAYS=$OPTARG
;;
u) UDAYS=$OPTARG
;;
t) TEST=1
;;
h) f_usage
exit 0
;;
*) f_usage
exit 2
;;
esac
done
shift $(($OPTIND - 1))
# Ensure the default number of days is passed.
if [ -z "$DDAYS" ]; then
echo "ERROR: The default days parameter is mandatory."
f_usage
exit $FAILURE
fi
f_checkdays $DDAYS
echo "`basename $0` Started `date`."
# Use test mode if specified.
if [ $TEST -eq 1 ]
then
RM=$TESTRM
RMDIR=$TESTRMDIR
MV=$TESTMV
TOUCH=$TESTTOUCH
echo "Running in TEST mode."
fi
# Set the number of days to the default if not explicitly set.
ADAYS=${ADAYS:-$DDAYS}; echo "Keeping audit logs for $ADAYS days."; f_checkdays $ADAYS
BDAYS=${BDAYS:-$DDAYS}; echo "Keeping background logs for $BDAYS days."; f_checkdays $BDAYS
CDAYS=${CDAYS:-$DDAYS}; echo "Keeping core dumps for $CDAYS days."; f_checkdays $CDAYS
NDAYS=${NDAYS:-$DDAYS}; echo "Keeping network logs for $NDAYS days."; f_checkdays $NDAYS
RDAYS=${RDAYS:-$DDAYS}; echo "Keeping clusterware logs for $RDAYS days."; f_checkdays $RDAYS
UDAYS=${UDAYS:-$DDAYS}; echo "Keeping user logs for $UDAYS days."; f_checkdays $UDAYS
# Check for the oratab file.
if [ -f /var/opt/oracle/oratab ]; then
ORATAB=/var/opt/oracle/oratab
elif [ -f /etc/oratab ]; then
ORATAB=/etc/oratab
else
echo "ERROR: Could not find oratab file."
exit $FAILURE
fi
# Build list of distinct Oracle Home directories.
OH=`egrep -i ":Y|:N" $ORATAB | grep -v "^#" | grep -v "\*" | cut -d":" -f2 | sort | uniq`
# Exit if there are not Oracle Home directories.
if [ -z "$OH" ]; then
echo "No Oracle Home directories to clean."
exit $SUCCESS
fi
# Get the list of running databases.
SIDS=`ps -e -o args | grep pmon | grep -v grep | awk -F_ '{print $3}' | sort`
# Gather information for each running database.
for ORACLE_SID in `echo $SIDS`
do
# Set the Oracle environment.
ORAENV_ASK=NO
export ORACLE_SID
. $ORAENV
if [ $? -ne 0 ]; then
echo "Could not set Oracle environment for $ORACLE_SID."
else
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$ORIGLD
ORAENV_ASK=YES
echo "ORACLE_SID: $ORACLE_SID"
# Get the audit_dump_dest.
ADUMPDEST=`f_getparameter audit_dump_dest`
if [ ! -z "$ADUMPDEST" ] && [ -d "$ADUMPDEST" 2>/dev/null ]; then
echo " Audit Dump Dest: $ADUMPDEST"
ADUMPDIRS="$ADUMPDIRS $ADUMPDEST"
fi
# Get the background_dump_dest.
BDUMPDEST=`f_getparameter background_dump_dest`
echo " Background Dump Dest: $BDUMPDEST"
if [ ! -z "$BDUMPDEST" ] && [ -d "$BDUMPDEST" ]; then
BDUMPDIRS="$BDUMPDIRS $BDUMPDEST"
fi
# Get the core_dump_dest.
CDUMPDEST=`f_getparameter core_dump_dest`
echo " Core Dump Dest: $CDUMPDEST"
if [ ! -z "$CDUMPDEST" ] && [ -d "$CDUMPDEST" ]; then
CDUMPDIRS="$CDUMPDIRS $CDUMPDEST"
fi
# Get the user_dump_dest.
UDUMPDEST=`f_getparameter user_dump_dest`
echo " User Dump Dest: $UDUMPDEST"
if [ ! -z "$UDUMPDEST" ] && [ -d "$UDUMPDEST" ]; then
UDUMPDIRS="$UDUMPDIRS $UDUMPDEST"
fi
fi
done
# Do cleanup for each Oracle Home.
for ORAHOME in `f_getuniq "$OH"`
do
# Get the standard audit directory if present.
if [ -d $ORAHOME/rdbms/audit ]; then
ADUMPDIRS="$ADUMPDIRS $ORAHOME/rdbms/audit"
fi
# Get the Cluster Ready Services Daemon (crsd) log directory if present.
if [ -d $ORAHOME/log/$HOSTNAME/crsd ]; then
CRSLOGDIRS="$CRSLOGDIRS $ORAHOME/log/$HOSTNAME/crsd"
fi
# Get the Oracle Cluster Registry (OCR) log directory if present.
if [ -d $ORAHOME/log/$HOSTNAME/client ]; then
OCRLOGDIRS="$OCRLOGDIRS $ORAHOME/log/$HOSTNAME/client"
fi
# Get the Cluster Synchronization Services (CSS) log directory if present.
if [ -d $ORAHOME/log/$HOSTNAME/cssd ]; then
CSSLOGDIRS="$CSSLOGDIRS $ORAHOME/log/$HOSTNAME/cssd"
fi
# Get the Event Manager (EVM) log directory if present.
if [ -d $ORAHOME/log/$HOSTNAME/evmd ]; then
EVMLOGDIRS="$EVMLOGDIRS $ORAHOME/log/$HOSTNAME/evmd"
fi
# Get the RACG log directory if present.
if [ -d $ORAHOME/log/$HOSTNAME/racg ]; then
RACGLOGDIRS="$RACGLOGDIRS $ORAHOME/log/$HOSTNAME/racg"
fi
done
# Clean the audit_dump_dest directories.
if [ ! -z "$ADUMPDIRS" ]; then
for DIR in `f_getuniq "$ADUMPDIRS"`; do
if [ -d $DIR ]; then
echo "Cleaning Audit Dump Directory: $DIR"
find $DIR -type f -name "*.aud" -mtime +$ADAYS -exec $RM {} \; 2>/dev/null
fi
done
fi
# Clean the background_dump_dest directories.
if [ ! -z "$BDUMPDIRS" ]; then
for DIR in `f_getuniq "$BDUMPDIRS"`; do
if [ -d $DIR ]; then
echo "Cleaning Background Dump Destination Directory: $DIR"
# Clean up old trace files.
find $DIR -type f -name "*.tr[c,m]" -mtime +$BDAYS -exec $RM {} \; 2>/dev/null
find $DIR -type d -name "cdmp*" -mtime +$BDAYS -exec $RMDIR {} \; 2>/dev/null
fi
if [ -d $DIR ]; then
# Cut the alert log and clean old ones.
for f in `find $DIR -type f -name "alert\_*.log" ! -name "alert_[0-9A-Z]*.[0-9]*.log" 2>/dev/null`; do
echo "Alert Log: $f"
f_cutlog $f
f_deletelog $f $BDAYS
done
fi
done
fi
# Clean the core_dump_dest directories.
if [ ! -z "$CDUMPDIRS" ]; then
for DIR in `f_getuniq "$CDUMPDIRS"`; do
if [ -d $DIR ]; then
echo "Cleaning Core Dump Destination: $DIR"
find $DIR -type d -name "core*" -mtime +$CDAYS -exec $RMDIR {} \; 2>/dev/null
fi
done
fi
# Clean the user_dump_dest directories.
if [ ! -z "$UDUMPDIRS" ]; then
for DIR in `f_getuniq "$UDUMPDIRS"`; do
if [ -d $DIR ]; then
echo "Cleaning User Dump Destination: $DIR"
find $DIR -type f -name "*.trc" -mtime +$UDAYS -exec $RM {} \; 2>/dev/null
fi
done
fi
# Cluster Ready Services Daemon (crsd) Log Files
for DIR in `f_getuniq "$CRSLOGDIRS $OCRLOGDIRS $CSSLOGDIRS $EVMLOGDIRS $RACGLOGDIRS"`; do
if [ -d $DIR ]; then
echo "Cleaning Clusterware Directory: $DIR"
find $DIR -type f -name "*.log" -mtime +$RDAYS -exec $RM {} \; 2>/dev/null
fi
done
# Clean Listener Log Files.
# Get the list of running listeners. It is assumed that if the listener is not running, the log file does not need to be cut.
ps -e -o args | grep tnslsnr | grep -v grep | while read LSNR; do
# Derive the lsnrctl path from the tnslsnr process path.
TNSLSNR=`echo $LSNR | awk '{print $1}'`
ORACLE_PATH=`dirname $TNSLSNR`
ORACLE_HOME=`dirname $ORACLE_PATH`
PATH=$ORACLE_PATH:$ORIGPATH
LD_LIBRARY_PATH=$ORACLE_HOME/lib:$ORIGLD
LSNRCTL=$ORACLE_PATH/lsnrctl
echo "Listener Control Command: $LSNRCTL"
# Derive the listener name from the running process.
LSNRNAME=`echo $LSNR | awk '{print $2}' | tr "[:upper:]" "[:lower:]"`
echo "Listener Name: $LSNRNAME"
# Get the listener version.
LSNRVER=`$LSNRCTL version | grep "LSNRCTL" | grep "Version" | awk '{print $5}' | awk -F. '{print $1}'`
echo "Listener Version: $LSNRVER"
# Get the TNS_ADMIN variable.
echo "Initial TNS_ADMIN: $TNS_ADMIN"
unset TNS_ADMIN
TNS_ADMIN=`$LSNRCTL status $LSNRNAME | grep "Listener Parameter File" | awk '{print $4}'`
if [ ! -z $TNS_ADMIN ]; then
export TNS_ADMIN=`dirname $TNS_ADMIN`
else
export TNS_ADMIN=$ORACLE_HOME/network/admin
fi
echo "Network Admin Directory: $TNS_ADMIN"
# If the listener is 11g, get the diagnostic dest, etc...
if [ $LSNRVER -ge 11 ]; then
# Get the listener log file directory.
LSNRDIAG=`$LSNRCTL<<EOF | grep log_directory | awk '{print $6}'
set current_listener $LSNRNAME
show log_directory
EOF`
echo "Listener Diagnostic Directory: $LSNRDIAG"
# Get the listener trace file name.
LSNRLOG=`lsnrctl<<EOF | grep trc_directory | awk '{print $6"/"$1".log"}'
set current_listener $LSNRNAME
show trc_directory
EOF`
echo "Listener Log File: $LSNRLOG"
# If 10g or lower, do not use diagnostic dest.
else
# Get the listener log file location.
LSNRLOG=`$LSNRCTL status $LSNRNAME | grep "Listener Log File" | awk '{print $4}'`
fi
# See if the listener is logging.
if [ -z "$LSNRLOG" ]; then
echo "Listener Logging is OFF. Not rotating the listener log."
# See if the listener log exists.
elif [ ! -r "$LSNRLOG" ]; then
echo "Listener Log Does Not Exist: $LSNRLOG"
# See if the listener log has been cut today.
elif [ -f $LSNRLOG.$TODAY ]; then
echo "Listener Log Already Cut Today: $LSNRLOG.$TODAY"
# Cut the listener log if the previous two conditions were not met.
else
# Remove old 11g+ listener log XML files.
if [ ! -z "$LSNRDIAG" ] && [ -d "$LSNRDIAG" ]; then
echo "Cleaning Listener Diagnostic Dest: $LSNRDIAG"
find $LSNRDIAG -type f -name "log\_[0-9]*.xml" -mtime +$NDAYS -exec $RM {} \; 2>/dev/null
fi
# Disable logging.
$LSNRCTL <<EOF
set current_listener $LSNRNAME
set log_status off
EOF
# Cut the listener log file.
f_cutlog $LSNRLOG
# Enable logging.
$LSNRCTL <<EOF
set current_listener $LSNRNAME
set log_status on
EOF
# Delete old listener logs.
f_deletelog $LSNRLOG $NDAYS
fi
done
echo "`basename $0` Finished `date`."
exit
在crontab中设置一个作业,每天晚上凌晨零点运行这个脚本,日志文件保留31天。
00 00 * * * /home/oracle/_cron/cls_oracle/cls_oracle.sh -d 31 > /home/oracle/_cron/cls_oracle/cls_oracle.sh.log 2>&1
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文章浏览阅读2.1w次。准备工具:可正常上网的MacBook Pro(基于intel的CPU)1:如果之前安装了Windows想安装Windows 11,请先备份数据。如果之前没有安装过Windows,请空降第四步2:跳转至Mac系统关机长按“option“,选择磁盘:MacHD3:清除原先安装的Windows到Mac界面后:启动台-工具-启动转换助理,打开-继续-恢复分区(输入本机管理员密码)一定要先备份好数据!!!4:下载映像打开内置浏览器至下载 Windows 10下载官方系统映像(64位ISO文_macbookpro安装win11
文章浏览阅读344次,点赞8次,收藏10次。NotePad2轻便够用的文本编辑器,可以拖拽打开文本,和notepad++的功能差不多,可以平行替代。_文本编辑器notepad2
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文章浏览阅读1k次。文章目录前言前面我们已经介绍过了passwd的使用,今天我们再来看一些特殊的用法查看帮助[root@zmedu-17~]#passwd--help用法:passwd[选项...]-k,--keep-tokens保持身份验证令牌不过期-d,--delete删除已命名帐号的密码(只有根用户才能进行此操作)-l,--lock..._linux passwd --lock
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文章浏览阅读2.5k次,点赞4次,收藏18次。SSD1306命令命令表单(D/C#=0, R/W#(WR#) = 0, E(RD#=1) 特殊状态除外)基本命令 D/C Hex D7 D6 D5 D4 D3 D2 D1 D0 命令 描述 0 81._ssd1306中文手册
文章浏览阅读8.2k次,点赞13次,收藏142次。TCP协议详解TCP服务的特点TCP头部结构TCP连接的建立和关闭(三次握手和四次挥手)TCP状态转移服务器端的状态转移过程客户端的的状态转移过程TIME_WAIT 状态超时重传拥塞控制TCP协议属于传输层协议。从通信和信息处理角度看,它属于面向通信部分的最高层,只有位于网络边缘的主机的协议栈才有传输层协议;同时也是用户功能中的最低层,一些重要的socket选项都和TCP协议相关。TCP服务的特点传输层协议主要有两个: TCP 协议和UDP协议。TCP协议相对于UDP协议的特点是:面向连接、字节流和可_sms、tcp/ip