深海游弋的鱼 – 默默的点滴

使用 WordPress 构筑的 Blog 最近总是会报告 “建立数据库连接时出错” ，查看 Apache 的日志得到如下信息

$ sudo vim /var/log/apache2/error.log

1	$ sudo vim /var/log/apache2/error.log

在日志的最后得到类似如下的内容

[Mon Jan 06 16:30:06 2014] [error] [client 5.10.83.83] WordPress SELECT * FROM wp_posts  WHERE (post_type = 'page' AND post_status = 'publish')     ORDER BY menu_order,wp_posts.post_title .......MySQL server has gone away

1	[Mon Jan 06 16:30:06 2014] [error] [client 5.10.83.83] WordPress SELECT * FROM wp_posts WHERE (post_type = 'page' AND post_status = 'publish') ORDER BY menu_order,wp_posts.post_title .......MySQL server has gone away

这个 “MySQL server has gone away” 有些莫名奇妙，MySql 怎么会无缘无故的没有了呢。
于是查看系统日志

$ sudo vim /var/log/syslog

1	$ sudo vim /var/log/syslog

看到如下的输出

Jan  6 16:30:05 AY130422143404983ad9 kernel: [236491.346180] Out of memory: Kill process 755 (mysqld) score 91 or sacrifice child
Jan  6 16:30:05 AY130422143404983ad9 kernel: [236491.346267] Killed process 755 (mysqld) total-vm:887016kB, anon-rss:45820kB, file-rss:0kB
Jan  6 16:30:05 AY130422143404983ad9 kernel: [236491.422036] init: mysql main process (755) killed by KILL signal
Jan  6 16:30:05 AY130422143404983ad9 kernel: [236491.422096] init: mysql main process ended, respawning

Jan 6 16:30:05 AY130422143404983ad9 kernel: [236491.346180] Out of memory: Kill process 755 (mysqld) score 91 or sacrifice child

Jan 6 16:30:05 AY130422143404983ad9 kernel: [236491.346267] Killed process 755 (mysqld) total-vm:887016kB, anon-rss:45820kB, file-rss:0kB

Jan 6 16:30:05 AY130422143404983ad9 kernel: [236491.422036] init: mysql main process (755) killed by KILL signal

Jan 6 16:30:05 AY130422143404983ad9 kernel: [236491.422096] init: mysql main process ended, respawning

可以明显看到，是由于系统内存不足，导致了 Linux 系统自带的 OOM Killer 动作。执行

$ free -lm

1	$ free -lm

可以看到，实际的内存已经严重不足了，这台机器只配置了512M内存，跑一阵子之后，系统的剩余内存不足 10MB的样子了。

没办法，花钱加内存到1G。悲剧的是，还是会死掉，具体解决办法可以查看

Ubuntu 12.04下安装配置Worker工作模式的Apache 支持PHP
Ubuntu 12.04 Apache2 安装 PHP-FPM 增强 PHP5-CGI 的功能

通过限制DefaultMaxClassProcessCount 的数量来限制php5-cgi 的数量来避免太多的并发进程耗尽资源。

两个APK 通过Content Provider 来共享数据，在Android 4.2.2 API 17 之前都是正常的，但是到Android 4.2.2 API 17 上面就会报告异常类似如下的异常信息

09-17 12:15:52.221: E/AndroidRuntime(4551): FATAL EXCEPTION: main
09-17 12:15:52.221: E/AndroidRuntime(4551): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.identifier.gamecenter.gctictactoe/com.identifier.gamecenter.game.MainActivity}: java.lang.SecurityException: Permission Denial: opening provider com.identifier.gamecenterapp.contentprovider.MyGamesContentProvider from ProcessRecord{42622078 4551:com.identifier.gamecenter.gctictactoe/u0a10108} (pid=4551, uid=10108) that is not exported from uid 10072
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.os.Looper.loop(Looper.java:137)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread.main(ActivityThread.java:5103)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at java.lang.reflect.Method.invokeNative(Native Method)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at java.lang.reflect.Method.invoke(Method.java:525)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at dalvik.system.NativeStart.main(Native Method)
09-17 12:15:52.221: E/AndroidRuntime(4551): Caused by: java.lang.SecurityException: Permission Denial: opening provider c.identifier.gamecenterapp.contentprovider.MyGamesContentProvider from ProcessRecord{42622078 4551:com.identifier.gamecenter.gctictactoe/u0a10108} (pid=4551, uid=10108) that is not exported from uid 10072
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.os.Parcel.readException(Parcel.java:1431)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.os.Parcel.readException(Parcel.java:1385)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityManagerProxy.getContentProvider(ActivityManagerNative.java:2611)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread.acquireProvider(ActivityThread.java:4515)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ContextImpl$ApplicationContentResolver.acquireUnstableProvider(ContextImpl.java:2036)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.content.ContentResolver.acquireUnstableProvider(ContentResolver.java:1149)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.content.ContentResolver.query(ContentResolver.java:398)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.content.ContentResolver.query(ContentResolver.java:357)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at ch.ethz.csg.wlanopp.gapi.GameCenterController.getIdByGameTitle(GameCenterController.java:602)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at ch.ethz.csg.wlanopp.gapi.GameCenterController.isRegistered(GameCenterController.java:343)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at ch.ethz.csg.wlanopp.gapi.GameCenterController.addGame(GameCenterController.java:352)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at ch.ethz.csg.gamecenter.gctictactoe.MainActivity.onCreate(MainActivity.java:130)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.Activity.performCreate(Activity.java:5133)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
09-17 12:15:52.221: E/AndroidRuntime(4551):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
09-17 12:15:52.221: E/AndroidRuntime(4551):     ... 11 more
09-17 12:20:52.487: I/Process(4551): Sending signal. PID: 4551 SIG: 9

09-17 12:15:52.221: E/AndroidRuntime(4551): FATAL EXCEPTION: main

09-17 12:15:52.221: E/AndroidRuntime(4551): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.identifier.gamecenter.gctictactoe/com.identifier.gamecenter.game.MainActivity}: java.lang.SecurityException: Permission Denial: opening provider com.identifier.gamecenterapp.contentprovider.MyGamesContentProvider from ProcessRecord{42622078 4551:com.identifier.gamecenter.gctictactoe/u0a10108} (pid=4551, uid=10108) that is not exported from uid 10072

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread.access$600(ActivityThread.java:141)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.os.Handler.dispatchMessage(Handler.java:99)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.os.Looper.loop(Looper.java:137)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread.main(ActivityThread.java:5103)

09-17 12:15:52.221: E/AndroidRuntime(4551): at java.lang.reflect.Method.invokeNative(Native Method)

09-17 12:15:52.221: E/AndroidRuntime(4551): at java.lang.reflect.Method.invoke(Method.java:525)

09-17 12:15:52.221: E/AndroidRuntime(4551): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)

09-17 12:15:52.221: E/AndroidRuntime(4551): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)

09-17 12:15:52.221: E/AndroidRuntime(4551): at dalvik.system.NativeStart.main(Native Method)

09-17 12:15:52.221: E/AndroidRuntime(4551): Caused by: java.lang.SecurityException: Permission Denial: opening provider c.identifier.gamecenterapp.contentprovider.MyGamesContentProvider from ProcessRecord{42622078 4551:com.identifier.gamecenter.gctictactoe/u0a10108} (pid=4551, uid=10108) that is not exported from uid 10072

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.os.Parcel.readException(Parcel.java:1431)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.os.Parcel.readException(Parcel.java:1385)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityManagerProxy.getContentProvider(ActivityManagerNative.java:2611)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread.acquireProvider(ActivityThread.java:4515)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ContextImpl$ApplicationContentResolver.acquireUnstableProvider(ContextImpl.java:2036)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.content.ContentResolver.acquireUnstableProvider(ContentResolver.java:1149)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.content.ContentResolver.query(ContentResolver.java:398)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.content.ContentResolver.query(ContentResolver.java:357)

09-17 12:15:52.221: E/AndroidRuntime(4551): at ch.ethz.csg.wlanopp.gapi.GameCenterController.getIdByGameTitle(GameCenterController.java:602)

09-17 12:15:52.221: E/AndroidRuntime(4551): at ch.ethz.csg.wlanopp.gapi.GameCenterController.isRegistered(GameCenterController.java:343)

09-17 12:15:52.221: E/AndroidRuntime(4551): at ch.ethz.csg.wlanopp.gapi.GameCenterController.addGame(GameCenterController.java:352)

09-17 12:15:52.221: E/AndroidRuntime(4551): at ch.ethz.csg.gamecenter.gctictactoe.MainActivity.onCreate(MainActivity.java:130)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.Activity.performCreate(Activity.java:5133)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)

09-17 12:15:52.221: E/AndroidRuntime(4551): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)

09-17 12:15:52.221: E/AndroidRuntime(4551): ... 11 more

09-17 12:20:52.487: I/Process(4551): Sending signal. PID: 4551 SIG: 9

在AndroidManifest.xml中原来的定义如下

<provider     
    android:name="com.identifier.gamecenterapp.contentprovider.MyGamesContentProvider"
    android:authorities="com.identifier.gamecenterapp.contentprovider" >
</provider>

<provider

android:name="com.identifier.gamecenterapp.contentprovider.MyGamesContentProvider"

android:authorities="com.identifier.gamecenterapp.contentprovider" >

</provider>

并且没有定义 android:targetSdkVersion

查找了很多地方，最终发现原因

Content providers are no longer exported by default. That is, the default value for the android:exported attribute is now “false". If it’s important that other apps be able to access your content provider, you must now explicitly set android:exported="true".

This change takes effect only if you set either android:targetSdkVersion or android:minSdkVersion to 17 or higher. Otherwise, the default value is still “true" even when running on Android 4.2 and higher.

Content providers are no longer exported by default. That is, the default value for the android:exported attribute is now “false". If it’s important that other apps be able to access your content provider, you must now explicitly set android:exported="true".

This change takes effect only if you set either android:targetSdkVersion or android:minSdkVersion to 17 or higher. Otherwise, the default value is still “true" even when running on Android 4.2 and higher.

具体的网页在 http://developer.android.com/about/versions/android-4.2.html

因此修改为如下即可也就是增加 android:exported="true"

<provider     
android:name="com.identifier.gamecenterapp.contentprovider.MyGamesContentProvider"
android:authorities="com.identifier.gamecenterapp.contentprovider"       
android:exported="true">
</provider>

<provider

android:name="com.identifier.gamecenterapp.contentprovider.MyGamesContentProvider"

android:authorities="com.identifier.gamecenterapp.contentprovider"

android:exported="true">

</provider>

日期: 2014 年 1 月 6 日

WordPress报告 “建立数据库连接时出错” 的问题

Android 4.2.2 API 17 Content Provider 报错 SecurityException: Permission Denial: opening provider

Mac 下的16进制编辑软件

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