Hi Mesos experts
I setup a small mesos cluster with 1 master and 6 slaves,
and deploy hdfs on the same cluster topology, both with root user role.
#cat spark-1.5.1-bin-hadoop2.6/conf/spark-env.sh
export MESOS_NATIVE_JAVA_LIBRARY=/usr/local/lib/libmesos.so
export
JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.91-2.6.2.1.el7_1.x86_64/jre/
export SPARK_EXECUTOR_URI=hdfs://test/spark-1.5.1-bin-hadoop2.6.tgz
When I run a simple SparkPi test
#export MASTER=mesos://Mesos_Master_IP:5050
#spark-1.5.1-bin-hadoop2.6/bin/run-example SparkPi 10000
I got this on slaves:
I1104 22:24:02.238471 14518 fetcher.cpp:414] Fetcher Info:
{"cache_directory":"\/tmp\/mesos\/fetch\/slaves\/556b49c1-7e6a-4f99-b320-c3f0c849e836-S6\/root","items":[{"action":"BYPASS_CACHE","uri":{"extract":true,"value":"hdfs:\/\/test\/spark-1.5.1-bin-hadoop2.6.tgz"}}],"sandbox_directory":"\/ws\/mesos\/slaves\/556b49c1-7e6a-4f99-b320-c3f0c849e836-S6\/frameworks\/556b49c1-7e6a-4f99-b320-c3f0c849e836-0003\/executors\/556b49c1-7e6a-4f99-b320-c3f0c849e836-S6\/runs\/9ec70f41-67d5-4a95-999f-933f3aa9e261","user":"root"}
I1104 22:24:02.240910 14518 fetcher.cpp:369] Fetching URI
'hdfs://test/spark-1.5.1-bin-hadoop2.6.tgz'
I1104 22:24:02.240931 14518 fetcher.cpp:243] Fetching directly into the
sandbox directory
I1104 22:24:02.240952 14518 fetcher.cpp:180] Fetching URI
'hdfs://test/spark-1.5.1-bin-hadoop2.6.tgz'
E1104 22:24:02.245264 14518 shell.hpp:90] Command 'hadoop version 2>&1'
failed; this is the output:
sh: hadoop: command not found
Failed to fetch 'hdfs://test/spark-1.5.1-bin-hadoop2.6.tgz': Skipping
fetch with Hadoop client: Failed to execute 'hadoop version 2>&1'; the
command was either not found or exited with a non-zero exit status: 127
Failed to synchronize with slave (it's probably exited)
As for "sh: hadoop: command not found", it indicates when mesos executes
"hadoop version" command,
it cannot find any valid hadoop command, but actually when I log into
the slave, "hadoop vesion"
runs well, because I update hadoop path into PATH env.
cat ~/.bashrc
export
JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.91-2.6.2.1.el7_1.x86_64/jre/
export HADOOP_PREFIX=/opt/hadoop-2.6.0
export HADOOP_HOME=$HADOOP_PREFIX
export HADOOP_COMMON_HOME=$HADOOP_PREFIX
export HADOOP_CONF_DIR=$HADOOP_PREFIX/etc/hadoop
export HADOOP_HDFS_HOME=$HADOOP_PREFIX
export HADOOP_MAPRED_HOME=$HADOOP_PREFIX
export HADOOP_YARN_HOME=$HADOOP_PREFIX
export PATH=$PATH:$HADOOP_PREFIX/sbin:$HADOOP_PREFIX/bin
I also try to set hadoop_home when launching mesos-slave, hmm, no luck,
the slave
complains it can find JAVA_HOME env when executing "hadoop version"
Finally I check the Mesos code where this error happens, it looks quite
straight forward.
./src/hdfs/hdfs.hpp
44 // HTTP GET on hostname:port and grab the information in the
45 // <title>...</title> (this is the best hack I can think of to get
46 // 'fs.default.name' given the tools available).
47 struct HDFS
48 {
49 // Look for `hadoop' first where proposed, otherwise, look for
50 // HADOOP_HOME, otherwise, assume it's on the PATH.
51 explicit HDFS(const std::string& _hadoop)
52 : hadoop(os::exists(_hadoop)
53 ? _hadoop
54 : (os::getenv("HADOOP_HOME").isSome()
55 ? path::join(os::getenv("HADOOP_HOME").get(),
"bin/hadoop")
56 : "hadoop")) {}
57
58 // Look for `hadoop' in HADOOP_HOME or assume it's on the PATH.
59 HDFS()
60 : hadoop(os::getenv("HADOOP_HOME").isSome()
61 ? path::join(os::getenv("HADOOP_HOME").get(),
"bin/hadoop")
62 : "hadoop") {}
63
64 // Check if hadoop client is available at the path that was set.
65 // This can be done by executing `hadoop version` command and
66 // checking for status code == 0.
67 Try<bool> available()
68 {
69 Try<std::string> command = strings::format("%s version", hadoop);
70
71 CHECK_SOME(command);
72
73 // We are piping stderr to stdout so that we can see the error (if
74 // any) in the logs emitted by `os::shell()` in case of failure.
75 Try<std::string> out = os::shell(command.get() + " 2>&1");
76
77 if (out.isError()) {
78 return Error(out.error());
79 }
80
81 return true;
82 }
It puzzled me for a while, am I missing something obviously?
Thanks in advance.
