nodetool sjk 

Runs Swiss Java Knife (SJK) commands to execute, troubleshoot, and monitor the database using MBeans.

Runs Swiss Java Knife (SJK) commands to execute, troubleshoot, and monitor the database using MBeans.

Synopsis 

nodetool sjk options command command_options
DataStax Enterprise 5.0 Installer No-Services and tarball installations:
installation_location/resources/cassandra/bin

Nodetool general options 

The following options apply to all nodetool commands.

Options
Short Long Description
-h --host Hostname or IP address.
-p --port Port number.
-pwf --password-file Password file path.
-pw --password Password.
-u --username Remote JMX agent username.
-- Separates an option from an argument that could be mistaken for a option.

Options 

General Swiss Java Knife options.

--commands
Displays a list of all SJK commands.
--help
Displays command specific help, for example nodetool sjk ttop --help.
-X, --verbose
Displays detailed diagnostics.

Commands 

DataStax supports running SJK commands from nodetool.

mxdump 

Prints serialized MBeans to JSON format.
Warning: Running the command without the -q (query) switch results in an error if a non-serializable type such as an mx4j Mbean is returned.
-q, --query 

Output selected MBeans by specifying the ObjectName; match patterns using the asterisk (*) and question mark (?) wildcards.

For example, to get all values for Garbage Collector:
nodetool sjk mxdump -q java.lang:type=GarbageCollector,name=*

gc 

Print GC (garbage collection) log messages for remote process.

For example, to print the GC log messages:
nodetool sjk gc
Note: No options for GC.

hh 

Heap histogram (hh) prints the class histogram, similar to jmap -histo. When no options are specified, prints complete histogram for all objects.

Note: For package installations, run nodetool with the account the runs the database.
For example, to print a histogram for young with a sample duration of 10000 milliseconds on a system with DSE package installation:
sudo -u cassandra nodetool sjk hh --young --sample-depth 10000ms -n 10
-d, --sample-depth 
Specify an integer and unit to set the sample duration for --dead-young or --young; default: 10000ms. To set the unit, use the following notation:
  • ms (milliseconds)
  • s (seconds)
  • m (minutes)
  • h (hours)
  • d (days)
--dead 
Prints histogram of dead objects.
--dead-young 
Prints histogram for sample of dead young objects. Use with -d to set the duration.
--live 
Prints histogram of live objects.
-n, --top-number 
Limits the number of buckets for N top buckets; default: 2147483647.
--young 
Prints histrogram for a sample of the new objects. Use with -d to set the duration.

mx 

Provides query and execution for Mbeans from the nodetool interface.

-all, --allMatched 
Process all matched MBeans.
-a, --arguments 
Arguments for MBean operation invocation.
-f, --field, --attribute 
MBean attribute
-b, --bean 
Mbean name.
-mc, --call 
Invokes MBean method. Default false.
-mg, --get 
Retrieves value of MBean attribute. Default false.
-mi, --info 
Display metadata for MBean. Default false.
--max-col-width 
Table column width threshold for formatting tabular data. Default 40.
-op, --operation 
MBean operation name to be called.
--quiet 
Avoid non-essential output; default: false.
-ms, --set 
Sets value for MBean attribute; default: false.
-v, --value
Value to set for MBean attribute.

jps 

Enhanced version of jps tool from the Java Development Kit (JDK) that lists the instrumented HotSpot Java Virtual Machines (JVMs) on the target system.

-fd, --filter-description

Use a wildcard expression to match the process description.

-fp, --filter-property
Use a wildcard expressions to match JVM system properties.
-pd, --process-details
Prints custom information related to a process; set to PID, MAIN, FDQN_MAIN, ARGS, Dsys-prop, or Dsys-prop.
Xjvm-flag
Prints custom information related to the specified JVM flag.

stcap 

Stack Capture dumps stack traces to file for further processing.

-e, --empty
Set to true to retain threads without stack trace in dump (ignored by default); default: false.
-f, --filter
Filters threads by name using Java RegEx syntax; default: .*
Note: The default value, period (.) followed by asterisk (*), allows any number of any characters, including nulls.
-l, --limit
Target number of traces to collect, once reached command terminates where 0 is unlimited; default: 0.
-m, --match-frame
Set to filtering string and only traces containing are included in the dump.
-o, --output 
Write the thread dump to the specified a file name.
-r, --rotate 
When specified output file would be rotated every N traces. Specify 0 for no rotation; default: 0.
-i, --sampler-interval 
Interval between polling MBeans; default: 0.
-t, --timeout 
Time until command terminate even without enough traces collected; default: 30000.

stcpy 

Stack Copy utility copies and filters dumps.

-e, --empty 
Set to true to retain threads without stack trace in dump (ignored by default); default: false.
-i, --input 
Input files.
--mask 
One or more masking rules, for example com.mycompany:com.somecompany; default: null.
-m, --match-frame 
Frame filter, only traces containing the string are included in dump.
-o, --output 
Set to filename. Writes thread dump to the specified file.
-ss, --subsample 
If below 1.0 some frames are randomly thrown away. For example, 0.1 retains only every 10th frame; default: 1.0.
-tf, --thread-filter
Filter threads by name using Java RegEx syntax; default: .*

ssa 

Stack Sample Analyzer for stack trace dumps.

--categorize 
Prints summary for provided categorization; no summary printed by default.
-cf, --categorizer-file 
Path to file with stack trace categorization definition.
-co, --csv-output 
Output data in CSV format; default: false.
-f, --file 
Path to stack dump file.
--flame 
Exports flame graph to SVG format; default: not included.
--histo 
Prints frame histogram; default: not included.
-nc, --named-class 
Defines name stack trace. Use with other options.
classes 
Use name=filter expression notation; default: no expression.
--print 
Print traces from file; default: not included.
-rc, --rainbow 
List of filters for rainbow coloring.
--ssa-help 
Provides additional information about SSA options; default: not shown.
-si, --summary-info 
Lists summaries.
--thread-info 
Prints per thread information summary; default: false.
-tn, --thread-name 
Filters thread name using Java RegEx syntax.
-tr, --time-range 
Filters time range.
-tz, --time-zone 
Time zone used for timestamps; default: UTC. Use --ssa-help for timezone notation.
--title 
Inserts a flame graph title; default: Flame Graph.
-tf, --trace-filter 
Applies filter to traces before processing. Use --ssa-help for more details about filter notation.
-tt, --trace-trim 
Positional filter trim frames to process. Use --ssa-help for more details about trace filters.
--width 
Flame graph width in pixels; default: 1200.

ttop 

Displays top threads from JVM process.

-f, --filter 
Wild card expression to filter threads by name.
-o, --order 
Sort order. Value tags: CPU, USER, SYS, ALLOC, NAME; default: CPU.
-ri, --report-interval 

Interval between CPU usage reports; default: 10000.

-si, --sampler-interval 
Interval between polling MBeans; default: 500.
-n, --top-number 
Number of threads to show; default: 20.