Logging

debug_backtraceAt
Sets the logging backtrace location. When a backtrace location is set and a log message is emitted at that location, the stack of the goroutine executing the log statement will be printed to stderr.
Client
Method Invocation
Console
debug.backtraceAt(location)
RPC
{"method": "debug_backtraceAt", "params": [string]}
Parameters
Name
Type
Description
location
string
The logging backtrace location specified as <filename>:<line>.
Return Value
None
Example
> debug.backtraceAt("server.go:443")
null
HTTP RPC
$ curl -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"debug_backtraceAt","params":["server.go:443"],"id":1}' http://localhost:8551
{"jsonrpc":"2.0","id":1,"result":null}
debug_setVMLogTarget
Sets the output target of vmlog precompiled contract. When the output target is a file, logs from vmlog calls in smart contracts will be written to DATADIR/log/vm.log. Here DATADIR is the directory specified by --datadir when launching klay. On the other hand, the output target is stdout, logs will be displayed like a debug message on the standard output.
Client
Method Invocation
Console
debug.setVMLogTarget(target)
RPC
{"method": "debug_setVMLogTarget", "params": [number]}
Parameters
Name
Type
Description
target
int
The output target (0: no output, 1: file, 2: stdout, 3: both) (default: 0)
Return Value
Type
Description
string
The output target.  See the examples below for the actual return values.
Example
Console
> debug.setVMLogTarget(0)
"no output"
​
> debug.setVMLogTarget(1)
"file"
​
> debug.setVMLogTarget(2)
"stdout"
​
> debug.setVMLogTarget(3)
"both file and stdout"
​
> debug.setVMLogTarget(4)
Error: target should be between 0 and 3
    at web3.js:3239:20
    at web3.js:6447:15
    at web3.js:5181:36
    at <anonymous>:1:1
HTTP RPC
$ curl -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"debug_setVMLogTarget","params":[3],"id":1}' http://localhost:8551
{"jsonrpc":"2.0","id":1,"result":"both file and stdout"}
debug_verbosity
Sets the logging verbosity ceiling. Log messages with level up to and including the given level will be printed.
(Level : 0=silent, 1=error, 2=warn, 3=info, 4=debug, 5=detail)
The verbosity of individual packages and source files can be raised using debug_vmodule.
Client
Method Invocation
Console
debug.verbosity(level)
RPC
{"method": "debug_vmodule", "params": [number]}
Parameters
Name
Type
Description
level
int
The logging verbosity level.
Return Value
None
Example
Console
> debug.verbosity(3)
null
HTTP RPC
$ curl -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"debug_verbosity","params":['3'],"id":1}' http://localhost:8551
{"jsonrpc":"2.0","id":1,"result":null}
debug_vmodule
Sets the logging verbosity pattern.
Client
Method Invocation
Console
debug.vmodule(module)
RPC
{"method": "debug_vmodule", "params": [string]}
Parameters
Name
Type
Description
module
string
The module name for logging.
Return Value
None
Example
Console
If you want to see messages from a particular Go package (directory) and all subdirectories, use
> debug.vmodule("p2p/*=5")
If you want to restrict messages to a particular package (e.g., p2p) but exclude subdirectories, use
> debug.vmodule("p2p=4")
If you want to see log messages from a particular source file, use
> debug.vmodule("server.go=3")
HTTP RPC
$ curl -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"debug_vmodule","params":["p2p=4"],"id":1}' http://localhost:8551
{"jsonrpc":"2.0","id":1,"result":null}
debug
Profiling
Last updated 3 months ago
Client	Method Invocation
Console	`debug.backtraceAt(location)`
RPC	`{"method": "debug_backtraceAt", "params": [string]}`
Name	Type	Description
location	string	The logging backtrace location specified as `<filename>:<line>`.