作者归档：杨龙

(24: Too many open files)

2018/04/26 23:32:58 [crit] 1457#0: *259351 open() “/usr/share/nginx/html/50x.html” failed (24: Too many open files), client: 112.17.247.117, server: ***, request: “GET /*** HTTP/1.1”, upstream: “***”, host: “***”

worker_rlimit_nofile 65535;

while read line无法读取最后一行的问题

while read line读取文件时，如果文件最后一行之后没有换行符\n,则read读取最后一行时遇到文件结束符EOF,循环终止,虽然此时$line内存有最后一行,但程序已经没有机会再处理此行,因此可以通过以下代码来解决此问题:

while read line || [[ -n ${line} ]]; do
…
done
这样当文件没有结束时不会测试-n $line,当遇到文件结束时,仍然可以通过测试$line是否有内容来进行继续处理。

http://ju.outofmemory.cn/entry/86710

MySQL自动备份到亚马逊S3

#!/bin/sh


# Updates etc at: https://github.com/woxxy/MySQL-backup-to-Amazon-S3

# Under a MIT license
# change these variables to what you need

MYSQLROOT=XXX

MYSQLPASS=XXXX

S3BUCKET=xx-mysql-backup

# DATABASE='--all-databases'

DATABASE=${1-default}

FILENAME=${DATABASE}

HOST=master

DUMPOPTION='--quick --single-transaction'

# the following line prefixes the backups with the defined directory. it must be blank or end with a /

S3PATH=mysql-backup/${DATABASE}

# when running via cron, the PATHs MIGHT be different. If you have a custom/manual MYSQL install, you should set this manually like MYSQLDUMPPATH=/usr/local/mysql/bin/

MYSQLDUMPPATH=

#tmp path.

TMP_PATH=/tmp/
DATESTAMP=$(date +".%Y-%m-%d.%H:%M:%S")

DELDATESTAMP=$(date -d"15 day ago 2017-04-16" +".%Y-%m-%d.%H:%M:%S")

DAY=$(date +"%d")

DAYOFWEEK=$(date +"%A")
PERIOD=${2-day}

if [ ${PERIOD} = "auto" ]; then

    if [ ${DAY} = "01" ]; then

        PERIOD=month

    elif [ ${DAYOFWEEK} = "Sunday" ]; then

        PERIOD=week

    else

        PERIOD=day

    fi

fi
echo "Selected period: $PERIOD."
echo "Starting backing up the database to a .gz file..."
# dump all databases

${MYSQLDUMPPATH}mysqldump -h${HOST} ${DUMPOPTION} --user=${MYSQLROOT} --password=${MYSQLPASS} ${DATABASE} | gzip > ${TMP_PATH}${FILENAME}.gz
echo "Done backing up the database to a file."

# echo "Starting compression..."
# tar czf ${TMP_PATH}${FILENAME}${DATESTAMP}.tar.gz ${TMP_PATH}${FILENAME}.sql

mv ${TMP_PATH}${FILENAME}.gz ${TMP_PATH}${FILENAME}${DATESTAMP}.gz
# echo "Done compressing the backup file."
# upload all databases

echo "Uploading the new backup..."

s3cmd put -f --check-md5 -s --continue-put ${TMP_PATH}${FILENAME}${DATESTAMP}.gz s3://${S3BUCKET}/${S3PATH}${PERIOD}/

echo "New backup uploaded."

if [ $? -ne 0 ]

then

    echo "Re uploading the backup file..."

    s3cmd put -f --check-md5 -s --continue-put ${TMP_PATH}${FILENAME}${DATESTAMP}.gz s3://${S3BUCKET}/${S3PATH}${PERIOD}/

    echo "Re upload backup file done."

fi
echo "Moving the backup from past $PERIOD to another folder..."

s3cmd mv --recursive s3://${S3BUCKET}/${S3PATH}${PERIOD}/${FILENAME}${DELDATESTAMP} s3://${S3BUCKET}/${S3PATH}previous_${PERIOD}/

echo "Past backup moved."
# we want at least two backups, two months, two weeks, and two days

echo "Removing old backup (15 ${PERIOD}s ago)..."

s3cmd del --recursive s3://${S3BUCKET}/${S3PATH}previous_${PERIOD}/

echo "Old backup removed."
# remove databases dump

# rm ${TMP_PATH}${FILENAME}.sql

echo "Removing the gz files..."

rm ${TMP_PATH}${FILENAME}${DATESTAMP}.gz

echo "Files removed."

echo "All done."

Quick Benchmark: Gzip vs Bzip2 vs LZMA vs XZ vs LZ4 vs LZO

Mariadb 修改数据目录，并且打开了SELinux，SELinux配置命令

Job for mariadb.service failed because the control process exited with error code. See “systemctl status mariadb.service” and “journalctl -xe” for details.

MySQL 8.0启动报错，也是这个问题（已经chown了）

mysqld: File ‘./binlog.index’ not found (OS errno 13 – Permission denied)

chcon -R -t mysqld_db_t /mnt/mysql

参考页面：https://www.thegeekstuff.com/2016/05/move-mysql-directory/

Google 应用内购买结算资料

实现应用内购买结算：

https://developer.android.google.cn/google/play/billing/billing_integrate.html?hl=zh-cn

字段参考：

https://developer.android.google.cn/google/play/billing/billing_reference.html?hl=zh-cn#getBuyIntent

# PHP服务端验证
$inappPurchaseData = Request::input('INAPP_PURCHASE_DATA');
$inappDataSignature = Request::input('INAPP_DATA_SIGNATURE');
$googlePublicKey = 'xxxx'; # google后台能获取到的

$publicKey = "-----BEGIN PUBLIC KEY-----" . PHP_EOL . chunk_split($googlePublicKey, 64, PHP_EOL) .
"-----END PUBLIC KEY-----";

$publicKeyHandle = openssl_get_publickey($publicKey);
$verify = openssl_verify($inappPurchaseData, base64_decode($inappDataSignature), 
$publicKeyHandle, OPENSSL_ALGO_SHA1);

# $verify == 1 则验证通过, 0 表示验证失败

nginx: [emerg] unknown directive “proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for” in

$remote_addr 可信时才能信任 X-Forwarded-For、$proxy_add_x_forwarded_for

nginx配置代理转发，部分配置如下

        location / {
            # index index.html index.htm index.php;
            # try_files $uri $uri/ /index.php$request_uri;
            proxy_set_header Host $host;
            #proxy_set_header X-Real-IP $remote_addr;
            #proxy_set_header X-Real-Port $remote_port;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_pass https://10.29.185.61:8063;
        }

$proxy_add_x_forwarded_forthe “X-Forwarded-For” client request header field with the $remote_addr variable appended to it, separated by a comma. If the “X-Forwarded-For” field is not present in the client request header, the $proxy_add_x_forwarded_for variable is equal to the $remote_addr variable.

“ X-Forward-For”客户端请求头字段，后面附加 $remote _ addr 变量，中间用逗号分隔。如果客户端请求头中没有“ X-Forward-For”字段，则 $proxy_add_x_forwarded_for 变量等于 $remote_addr 变量。

MySQL GET_LOCK函数实现MySQL加锁

GET_LOCK(str,timeout)

Tries to obtain a lock with a name given by the string str, using a timeout of timeout seconds. A negative timeout value means infinite timeout. The lock is exclusive. While held by one session, other sessions cannot obtain a lock of the same name.

尝试使用超时秒数的超时获得一个由字符串str给出的名称的锁。
负超时值意味着无限超时。
锁是独占的。
只能由一个会话持有，其他会话无法获得同名的锁。

参考：https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
参考：https://blog.csdn.net/tangtong1/article/details/51792617

shadowsocks服务端快速搭建

Install (centos7)

yum install python-setuptools && easy_install pip
pip install git+https://github.com/shadowsocks/shadowsocks.git@master

Usage

ssserver -p 443 -k password -m aes-256-cfb

To run in the background:

sudo ssserver -p 443 -k password -m aes-256-cfb --user nobody -d start

To stop:

sudo ssserver -d stop

To check the log:

sudo less /var/log/shadowsocks.log

Error while reading line from the server.

环境：php7.1、centos7、redis3.2.11
故障现象：php命令行环境下blpop 的时候是不是出现：blpop Error while reading line from the server.
blpop的等待时间是设置为了15秒
—-

Redis经常出现Error while reading line from the server.

cat /proc/sys/net/ipv4/tcp_timestamps
发现返回1
将其设置为0
echo 0 > /proc/sys/net/ipv4/tcp_timestamps

参考：http://blog.csdn.net/jueshengtianya/article/details/50440696

net.ipv4.tcp_timestamps=0

说明：时间戳可以避免序列号的卷绕。一个1Gbps的链路肯定会遇到以前用过的序列号。时间戳能够让内核接受这种“异常”的数据包。这里需要将其关掉。

值为0（禁用时间戳）

值为1（启用时间戳）

—-

然而进行以上操作以后还是会出现