You are viewing a plain text version of this content. The canonical link for it is here.
Posted to notifications@logging.apache.org by "Arthur Gavlyukovskiy (Jira)" <ji...@apache.org> on 2022/07/19 17:22:00 UTC
[jira] [Updated] (LOG4J2-3556) JsonTemplateLayout truncation ignores exception cause
[ https://issues.apache.org/jira/browse/LOG4J2-3556?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Arthur Gavlyukovskiy updated LOG4J2-3556:
-----------------------------------------
Description:
Stacktrace truncation is helpful to reduce the size of the event, but current approach implemented in LOG4J2-2993 completely removes any "Caused by:" that might be in the stacktrace, while those are the most useful parts of stacktrace.
I'm using the modified EcsLayout.json with suggested truncation point
{code:java}
"error.stack_trace": {
"$resolver": "exception",
"field": "stackTrace",
"stackTrace": {
"stringified": {
"truncation": {
"pointMatcherStrings": ["at javax.servlet.http.HttpServlet.service"],
"suffix": "\n\t<skipped internal frames>"
}
}
}
} {code}
and the stacktrace I saw on a real production server was rendered as
{code:java}
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
at javax.servlet.http.HttpServlet.service
<skipped internal frames> {code}
which doesn't show anything about origin of the error.
The fix should be relatively simple - change StackTraceStringResolver.truncate method to
{code:java}
private void truncate(
final TruncatingBufferedPrintWriter writer,
final int index) {
int causedByIndex = writer.indexOf("Caused by:");
CharSequence causedBy = null;
if (causedByIndex != -1) {
causedBy = writer.subSequence(causedByIndex - 1, writer.position());
}
writer.position(index);
writer.print(truncationSuffix);
if (causedByIndex != -1) {
writer.print(causedBy);
}
}
{code}
and it correctly displays the stack trace:
{code:java}
java.lang.IllegalArgumentException: wrapper error
at reproducer.log4jjsontemplate.StackTraceController.test(StackTraceController.java:18)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
at javax.servlet.http.HttpServlet.service
<skipped internal frames>
Caused by: java.lang.NullPointerException: original error
at reproducer.log4jjsontemplate.StackTraceController.test(StackTraceController.java:16)
... 50 more {code}
I have created an MRE [here|https://github.com/gavlyukovskiy/log4j-json-template-reproducer] where you can find more details and monkey patch on a [separate branch|https://github.com/gavlyukovskiy/log4j-json-template-reproducer/tree/monkey-patch].
was:
Stacktrace truncation is helpful to reduce the size of the event, but current approach implemented in LOG4J2-2993 completely removes any "Caused by:" that might be in the stacktrace, while those are the most useful parts of stacktrace.
I'm using the modified EcsLayout.json with suggested truncation point
{code:java}
"error.stack_trace": {
"$resolver": "exception",
"field": "stackTrace",
"stackTrace": {
"stringified": {
"truncation": {
"pointMatcherStrings": ["at javax.servlet.http.HttpServlet.service"],
"suffix": "\n\t<skipped internal frames>"
}
}
}
} {code}
and the stacktrace I saw on a real production server was rendered as
{code:java}
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
at javax.servlet.http.HttpServlet.service
<skipped internal frames> {code}
which doesn't show anything about origin of the error.
The fix should be relatively simple - change StackTraceStringResolver.truncate method to
{code:java}
private void truncate(
final TruncatingBufferedPrintWriter writer,
final int index) {
int causedByIndex = writer.indexOf("Caused by:");
CharSequence causedBy = null;
if (causedByIndex != -1) {
causedBy = writer.subSequence(causedByIndex - 1, writer.position());
}
writer.position(index);
writer.print(truncationSuffix);
if (causedByIndex != -1) {
writer.print(causedBy);
}
}
{code}
and it correctly displays the stack trace.
I have created an MRE [here|https://github.com/gavlyukovskiy/log4j-json-template-reproducer] where you can find more details and monkey patch on a [separate branch|https://github.com/gavlyukovskiy/log4j-json-template-reproducer/tree/monkey-patch].
> JsonTemplateLayout truncation ignores exception cause
> -----------------------------------------------------
>
> Key: LOG4J2-3556
> URL: https://issues.apache.org/jira/browse/LOG4J2-3556
> Project: Log4j 2
> Issue Type: Bug
> Components: JsonTemplateLayout
> Reporter: Arthur Gavlyukovskiy
> Priority: Minor
>
> Stacktrace truncation is helpful to reduce the size of the event, but current approach implemented in LOG4J2-2993 completely removes any "Caused by:" that might be in the stacktrace, while those are the most useful parts of stacktrace.
> I'm using the modified EcsLayout.json with suggested truncation point
> {code:java}
> "error.stack_trace": {
> "$resolver": "exception",
> "field": "stackTrace",
> "stackTrace": {
> "stringified": {
> "truncation": {
> "pointMatcherStrings": ["at javax.servlet.http.HttpServlet.service"],
> "suffix": "\n\t<skipped internal frames>"
> }
> }
> }
> } {code}
> and the stacktrace I saw on a real production server was rendered as
> {code:java}
> org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
> at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
> at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
> at javax.servlet.http.HttpServlet.service
> <skipped internal frames> {code}
> which doesn't show anything about origin of the error.
>
> The fix should be relatively simple - change StackTraceStringResolver.truncate method to
> {code:java}
> private void truncate(
> final TruncatingBufferedPrintWriter writer,
> final int index) {
> int causedByIndex = writer.indexOf("Caused by:");
> CharSequence causedBy = null;
> if (causedByIndex != -1) {
> causedBy = writer.subSequence(causedByIndex - 1, writer.position());
> }
> writer.position(index);
> writer.print(truncationSuffix);
> if (causedByIndex != -1) {
> writer.print(causedBy);
> }
> }
> {code}
> and it correctly displays the stack trace:
> {code:java}
> java.lang.IllegalArgumentException: wrapper error
> at reproducer.log4jjsontemplate.StackTraceController.test(StackTraceController.java:18)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
> at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.base/java.lang.reflect.Method.invoke(Method.java:568)
> at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
> at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
> at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
> at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
> at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
> at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
> at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067)
> at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963)
> at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
> at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
> at javax.servlet.http.HttpServlet.service
> <skipped internal frames>
> Caused by: java.lang.NullPointerException: original error
> at reproducer.log4jjsontemplate.StackTraceController.test(StackTraceController.java:16)
> ... 50 more {code}
>
> I have created an MRE [here|https://github.com/gavlyukovskiy/log4j-json-template-reproducer] where you can find more details and monkey patch on a [separate branch|https://github.com/gavlyukovskiy/log4j-json-template-reproducer/tree/monkey-patch].
--
This message was sent by Atlassian Jira
(v8.20.10#820010)