I have been using Eclipse for Android (most up to date version), for a while with no problems with the Logcat. For an unknown reason, Logcat is no longer retaining the debug messages. Logcat is getting cleared in about 5 seconds . Is there any way to prevent the auto-clearing of Logcat messages? Otherwise I am unable to read the messages.
Change your LogCat buffer length:
Window / Preferences / Android / LogCat / Maximum number of LogCat messages in buffer _
Set it to 0 for unlimited size (thanks to the commenter below)
Its happens when there is too many logcat rows. It automatically delete all after reaching maximum number defined in preferences (5000 rows by default in Eclipse), both filtered and not filtered rows.
Fortunetly, you can change maximum number in:
Window > Preferences > Android > LogCat > Maximum number of LogCat messages in buffer
I have the same problem, but only with Sony Xperia C and Android 4.2.2. Every phone have different level of logging.
You can use breakpoints where you print the messages and debug them by F6/F8 keys after that. So you can see all the messages by step.
来源：https://stackoverflow.com/questions/12442892/eclipse-android-logcat-clearing-too-fast