Issue with Java on Challenge #1: Echo

[tharun]

Hi, I’m trying to solve Distributed Systems Echo Challenge. I’ve created a Java Maven project and added the echo demo code to the project.

When I execute this command :
./maelstrom test -w echo --bin <my_jar_path> --node-count 1 --time-limit 10

Error:

Full STDERR logs are available in /Users/installations/maelstrom/store/echo/20230421T181934.006+0530/node-logs/n0.log
at slingshot.support$stack_trace.invoke(support.clj:201)
at maelstrom.process$stop_node_BANG_.invokeStatic(process.clj:239)
at maelstrom.process$stop_node_BANG_.invoke(process.clj:217)
at maelstrom.db$db$reify__16142.teardown_BANG_(db.clj:75)
at jepsen.db$fn__8744$G__8725__8748.invoke(db.clj:12)
at jepsen.db$fn__8744$G__8724__8753.invoke(db.clj:12)
at clojure.core$partial$fn__5908.invoke(core.clj:2642)
at jepsen.control$on_nodes$fn__8599.invoke(control.clj:314)
at clojure.lang.AFn.applyToHelper(AFn.java:154)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.core$apply.invokeStatic(core.clj:667)
at clojure.core$with_bindings_STAR_.invokeStatic(core.clj:1990)
at clojure.core$with_bindings_STAR_.doInvoke(core.clj:1990)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invokeStatic(core.clj:671)
at clojure.core$bound_fn_STAR_$fn__5818.doInvoke(core.clj:2020)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at dom_top.core$real_pmap_helper$build_thread__211$fn__212.invoke(core.clj:163)
at clojure.lang.AFn.applyToHelper(AFn.java:152)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.core$apply.invokeStatic(core.clj:667)
at clojure.core$with_bindings_STAR_.invokeStatic(core.clj:1990)
at clojure.core$with_bindings_STAR_.doInvoke(core.clj:1990)
at clojure.lang.RestFn.invoke(RestFn.java:425)
at clojure.lang.AFn.applyToHelper(AFn.java:156)
at clojure.lang.RestFn.applyTo(RestFn.java:132)
at clojure.core$apply.invokeStatic(core.clj:671)
at clojure.core$bound_fn_STAR_$fn__5818.doInvoke(core.clj:2020)
at clojure.lang.RestFn.invoke(RestFn.java:397)
at clojure.lang.AFn.run(AFn.java:22)
at java.base/java.lang.Thread.run(Thread.java:833)
ERROR [2023-04-21 18:19:46,219] main - jepsen.cli Oh jeez, I’m sorry, Jepsen broke. Here’s why:
clojure.lang.ExceptionInfo: Node n0 crashed with exit status 2. Before crashing, it wrote to STDOUT:

/Users/werwee/eddy/target/eddy-1.0-SNAPSHOT.jar: line 1: PK: command not found
/Users/werwee/eddy/target/eddy-1.0-SNAPSHOT.jar: line 2: ???V: command not found
/Users/werwee/eddy/target/eddy-1.0-SNAPSHOT.jar: line 3:??VZ???META-INF/MANIFEST.MFE?M: No such file or directory
/Users/werwee/eddy/target/eddy-1.0-SNAPSHOT.jar: line 4: ?0@??@?
d?: command not found
/Users/werwee/eddy/target/eddy-1.0-SNAPSHOT.jar: line 14: syntax error near unexpected token )' /Users/werwee/eddy/target/eddy-1.0-SNAPSHOT.jar: line 14: O?z

[tom93]

The --bin option takes an executable file, but .jar files are not executables (they need to be executed using java -jar your-jar.jar). You need to create a shell script wrapper; see the Maelstrom Java demo for an example, it’s basically a file with the following code:

#!/bin/sh
exec java -jar your-jar.jar

You’ll need to run chmod +x on this file to mark it as executable, and then you can pass it as the argument for the --bin option.