Neo4j refused to connect - browser

Characteristics :
Linux
Neo4j version 3.2.1
Access on remote
Installation
I Had install neo4j and gave the folder chmod 777 .
Im running it remotely on my machine and I had already enabled non local access
Doing NEo4j start i get this message
Active database: graph.db
Directories in use:
home: /home/cloudera/Muna/apps/neo4j
config: /home/cloudera/Muna/apps/neo4j/conf
logs: /home/cloudera/Muna/apps/neo4j/logs
plugins: /home/cloudera/Muna/apps/neo4j/plugins
import: /home/cloudera/Muna/apps/neo4j/import
data: /home/cloudera/Muna/apps/neo4j/data
certificates: /home/cloudera/Muna/apps/neo4j/certificates
run: /home/cloudera/Muna/apps/neo4j/run
Starting Neo4j.
WARNING: Max 1024 open files allowed, minimum of 40000 recommended. See the Neo4j manual.
Started neo4j (pid 9469). It is available at http://0.0.0.0:7474/
There may be a short delay until the server is ready.
See /home/cloudera/Muna/apps/neo4j/logs/neo4j.log for current status.
and it is not connecting in the browser .
running neo4j console
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (malloc) failed to allocate 409600000 bytes for AllocateHeap
# An error report file with more information is saved as:
# /home/cloudera/hs_err_pid18598.log
where could the problem be coming from ?

Firstly, you should set the maximum open files to 40000, which is the recommended value. Then you do not get the WARNING. Like this: http://neo4j.com/docs/1.6.2/configuration-linux-notes.html
Secondly,'failed to allocate memory' means that the Java virtual machine cannot allocate the memory you start it with.
It can be a misconfiguration, or you physically do not have enough memory.
Please read the memory sizing guidelines here:
https://neo4j.com/docs/operations-manual/current/performance/

Related

Is setting the linux memory to unlimit will have an adverse effect?

I am running MPI job in linux server. I got error:
--------------------------------------------------------------------------
The OpenFabrics (openib) BTL failed to initialize while trying to
allocate some locked memory. This typically can indicate that the
memlock limits are set too low. For most HPC installations, the
memlock limits should be set to "unlimited". The failure occured
here:
Local host: yw0431
OMPI source: ../../../../../ompi/mca/btl/openib/btl_openib_component.c:1216
Function: ompi_free_list_init_ex_new()
Device: mlx4_0
Memlock limit: 65536
You may need to consult with your system administrator to get this
problem fixed. This FAQ entry on the Open MPI web site may also be
helpful:
http://www.open-mpi.org/faq/?category=openfabrics#ib-locked-pages
--------------------------------------------------------------------------
--------------------------------------------------------------------------
WARNING: There was an error initializing an OpenFabrics device.
Local host: yw0431
Local device: mlx4_0
--------------------------------------------------------------------------
[yw0431:20193] 11 more processes have sent help message help-mpi-btl-openib.txt / init-fail-no-mem
[yw0431:20193] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages
[yw0431:20193] 11 more processes have sent help message help-mpi-btl-openib.txt / error in device init
forrtl: error (78): process killed (SIGTERM)
it means that my linux server have locked memory with 65M, but my job needed more memory. I think 2G should be emough.
I have found a solution about ulimiting the memory:
ulimit -l unlimited
But i am worried that i will cause system crash or some bad things happen.
so can i set "ulimit -l umlimited"?
When you set ulimit as unlimited and your process starting using memory exhaustively then OOM killer will kill ur job for system stability,I would set the ulimit as 80 to 90% of RAM of instead of unlimited.

i have just begun to use android studio and i cant seem to get my gradle to sync with my application. here is what it shows :

7:46:20 PM Gradle sync started
7:46:35 PM Gradle sync failed: Unable to start the daemon process.
This problem might be caused by incorrect configuration of the daemon.
For example, an unrecognized jvm option is used.
Please refer to the user guide chapter on the daemon at https://docs.gradle.org/2.10/userguide/gradle_daemon.html
Please read the following process output to find out more:
-----------------------
Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
Consult IDE log for more details (Help | Show Log)
the jvm version is 1.7.0_79
and the studio version is 2.1.1
Error occurred during initialization of VM Could not reserve enough space for object heap Error: Could not create the Java Virtual Machine.
There's no space available in RAM. To fix go to /android-studio-dir/bin and edit studio.vmoptions and studio64.vmoptions to increment the -Xmx and to reserve more memory to Java. Note that the number of processes active may influence on that.
Probably, the /tmp location is full..
Found this somewhere..
Use df command
df
You should see an output with a line like this:
tmpfs 102400 102312 88 100% /tmp
So to change the size of the tmp file:
sudo mount -o remount,size=2G /tmp
Done! Now, It should work..

Restart dead accumulo tablet server

I use a single-instance Accumulo database. It worked all fine until I tried to ingest multiple data (following this tutorial), then my tablet sever died.
I tried to restart it (using bin/start-all or bin/start-here) but it did not work. Then I restarted the whole server and it seams, that bin/start-all starts the tablet server first:
WARN : Using Zookeeper /root/Installs/zookeeper-3.4.6/zookeeper-3.4.6. Use version 3.3.0 or greater to avoid zookeeper deadlock bug.
Starting monitor on localhost
WARN : Max open files on localhost is 1024, recommend 32768
Starting tablet servers .... done
Starting tablet server on 46.101.229.80
WARN : Max open files on 46.101.229.80 is 1024, recommend 32768
OpenJDK Client VM warning: You have loaded library /root/Installs/hadoop-2.6.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'.
2016-01-27 04:44:18,778 [util.NativeCodeLoader] WARN : Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2016-01-27 04:44:23,770 [fs.VolumeManagerImpl] WARN : dfs.datanode.synconclose set to false in hdfs-site.xml: data loss is possible on hard system reset or power loss
2016-01-27 04:44:23,803 [server.Accumulo] INFO : Attempting to talk to zookeeper
2016-01-27 04:44:24,246 [server.Accumulo] INFO : ZooKeeper connected and initialized, attempting to talk to HDFS
2016-01-27 04:44:24,802 [server.Accumulo] INFO : Connected to HDFS
Starting master on 46.101.229.80
WARN : Max open files on 46.101.229.80 is 1024, recommend 32768
Starting garbage collector on 46.101.229.80
WARN : Max open files on 46.101.229.80 is 1024, recommend 32768
Starting tracer on 46.101.229.80
WARN : Max open files on 46.101.229.80 is 1024, recommend 32768
But checking the monitor the tablet server is still dead.
The tserver_46.101.229.80.err-log ist empty, the tserver_46.101.229.80.out-log says:
OpenJDK Client VM warning: You have loaded library /root/Installs/hadoop-2.6.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'.
#
# java.lang.OutOfMemoryError: Java heap space
# -XX:OnOutOfMemoryError="kill -9 %p"
# Executing /bin/sh -c "kill -9 3225"...
How can I get the tabletServer up again?
I use a 32-bit 14.04 Linux of DigitalOcean, Hadoop 2.6, ZooKeeper 3.4.6 and Accuulo 1.6.4
If the TabletServer is repeatedly crashing with an OutOfMemoryError, you need to increase the JVM maximum heap size via the -Xmx option in the ACCUMULO_TSERVER_OPTS in accumulo-env.sh.

Spark - UbuntuVM - insufficient memory for the Java Runtime Environment

I'm trying to install Spark1.5.1 on Ubuntu14.04 VM. After un-tarring the file, I changed the directory to the extracted folder and executed the command "./bin/pyspark" which should fire up the pyspark shell. But I got an error message as follows:
[ OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000c5550000, 715849728, 0) failed;
error='Cannot allocate memory' (errno=12) There is insufficient
memory for the Java Runtime Environment to continue.
Native memory allocation (malloc) failed to allocate 715849728 bytes
for committing reserved memory.
An error report file with more information is saved as:
/home/datascience/spark-1.5.1-bin-hadoop2.6/hs_err_pid2750.log ]
Could anyone please give me some directions to sort out the problem?
We need to set spark.executor.memory in conf/spark-defaults.conf file to a value specific to your machine. For example,
usr1#host:~/spark-1.6.1$ cp conf/spark-defaults.conf.template conf/spark-defaults.conf
nano conf/spark-defaults.conf
spark.driver.memory 512m
For more information, refer to the official documentation: http://spark.apache.org/docs/latest/configuration.html
Pretty much what it says. It wants 7GB of RAM. So give the VM ~ 8GB of RAM.

cassandra connection error : Could not connect to localhost:9160

my cassandra was working well but suddenly it stop working!
when i use cqlsh command i get this error:
connection error : Could not connect to localhost:9160
and in output.log file i seeing this :
Service exit with a return value of 1
OpenJDK Client VM warning: Insufficient space for shared memory file:
/tmp/hsperfdata_cassandra/10963
Try using the -Djava.io.tmpdir= option to select an alternate temp location.
INFO 12:23:31,307 Logging initialized
log4j:ERROR Failed to flush writer,
java.io.IOException: No space left on device
at java.io.FileOutputStream.writeBytes(Native Method)
at java.io.FileOutputStream.write(FileOutputStream.java:297)
at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:220)
at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:290)
at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:294)
at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:140)
at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229)
at org.apache.log4j.helpers.QuietWriter.flush(QuietWriter.java:59)
at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:324)
at org.apache.log4j.RollingFileAppender.subAppend(RollingFileAppender.java:276)
at org.apache.log4j.WriterAppender.append(WriterAppender.java:162)
at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)
at org.apache.log4j.Category.callAppenders(Category.java:206)
at org.apache.log4j.Category.forcedLog(Category.java:391)
at org.apache.log4j.Category.info(Category.java:666)
at org.apache.cassandra.service.CassandraDaemon.initLog4j(CassandraDaemon.java:118)
at org.apache.cassandra.service.CassandraDaemon.<clinit>(CassandraDaemon.java:65)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
at java.lang.Class.newInstance0(Class.java:374)
at java.lang.Class.newInstance(Class.java:327)
at org.apache.commons.daemon.support.DaemonLoader.load(DaemonLoader.java:190)
INFO 12:23:31,332 32bit JVM detected. It is recommended to run Cassandra on a 64bit JVM for better performance.
INFO 12:23:31,335 JVM vendor/version: OpenJDK Client VM/1.6.0_27
WARN 12:23:31,335 OpenJDK is not recommended. Please upgrade to the newest Oracle Java release
INFO 12:23:31,335 Heap size: 252641280/253689856
INFO 12:23:31,335 Classpath: /usr/share/cassandra/lib/antlr-3.2.jar:/usr/share/cassandra/lib/avro-1.4.0-fixes.jar:/usr/share/cassandra/lib/avro-1.4.0-sources-fixes.jar$
INFO 12:23:31,691 JNA mlockall successful
INFO 12:23:31,715 Loading settings from filService exit with a return value of 1
OpenJDK Client VM warning: Insufficient space for shared memory file:
can somebody help me? :(
The /tmp directory on your host isn't large enough for the temp files that cassandra wishes to make. The temp files are related to the amount of data in the system. As your database is larger now than it was in the past, it started before but it does not start now.
Check the status of the /tmp directory with df. Here is my system
$ df /tmp
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda6 570881944 350121276 191761552 65% /
To alter the place that is used for these temp files like the error says set java.io.tmpdir
On my system (Ubuntu Linux) this can be done by editing the end of the file /etc/cassandra/cassandra-env.sh
JVM_OPTS="$JVM_OPTS $JVM_EXTRA_OPTS -Djava.io.tmpdir=/opt"
Ensure that the new temp directory has sufficient space and that the permissions are correct, probably allowing read/write for the cassandra user would be enough

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