GeoSPARQL for Apache Jena Fuseki - jena

Jena Fuseki works fine, but the GeoSPARQL version not so much (https://github.com/galbiston/geosparql-fuseki).
It'll fire up (supposedly)
11:12:46 INFO GeosparqlServer :: GeoSPARQL Server: Running - Port: 3030, Dataset: /ds, Loopback Only: true, Allow Update: false
11:12:46 INFO Server :: Start Fuseki (port=3030)
I tend to use Postman to test these kind of things, but http://localhost:3030 just returns a 404.
So my first question is whether it's really actually running or not. It would appear that it isn't.
My second question (for when it is running) relates to getting data into it. There's not front-end of the thing but a command line command of:
s-put http://localhost:3030/ default geonames.ttl
But s-put doesn't appear to be an executable, so how does one call it?

Related

Is any way to start go_binary before java_test?

Our project has a few GRPC servers defined as go_binary targets. We develop client SDKs for Java and Python applications and we would like to use java_test and py_test. Is any way to start a specific go_binary target before java_test or py_test?
You can create a test harness that starts the gRPC server before running the tests. For example, you could add the binary to the data attribute of the test, and then started it beforehand:
go_binary(
name = "my_grpc_server",
[...]
)
py_test(
name = "my_test",
[...]
data = [":my_grpc_server"],
)
and then inside the test file:
class ClientTestCase(unittest.TestCase):
def setUp(self):
r = runfiles.Create()
self.server = subprocess.Popen([r.Rlocation("path/to/my_grpc_server")])
def tearDown(self):
self.server.terminate()
self.server.wait()
This example is very simple, you'll probably run into issues regarding the availability of the port the server listens on, or waiting for the server to start up. You could add flags to your gRPC server to allow communication over a domain socket, or make it listen on an unused port and have the test parse the port number from the server's log output.
For details on finding the server with runfiles: https://github.com/bazelbuild/bazel/blob/a7a0d48fbeb059ee60e77580e5d05baeefdd5699/tools/python/runfiles/runfiles.py#L16-L58
If you find yourself copy-pasting this pattern a lot, or having to implement it in multiple languages, you could try using an sh_test() rule to wrap the underlying py_test or java_test, and to start the server, then start the test with an environment variable telling it how to reach the server (eg MY_GRPC_SERVER_ADDRESS=localhost:${test_port}.

No such property: ToInputStream for class: Script4

I have a situation where I want to import my graph data to database.I am having janusgraph(latest version) running with cassandra(version 3) and elasticsearch(version 6.6.0) using Docker.I have been suggested to use gryo format.So I have tried this command
graph.io(IoCore.gryo()).reader().create().readGraph(ToInputStream.from("my_graph.kryo"), graph);
but ended up with an error
No such property: ToInputStream for class: Script4
The documentation I am following is here.Please take a look and put me in a right procedure. Thanks in advance!
ToInputStream is not a function of Gremlin or JanusGraph. I believe that it is only a function of IBM Compose so unless you are running JanusGraph on that specific platform, this command will not work.
Versions of JanusGraph that utilize TinkerPop 3.4.x will support the io() step and this is the preferred manner in which to load gryo (as well as graphson and graphml) files.
Graph graph = ... // setup JanusGraph instance
GraphTraversalSource g = traversal().withGraph(graph); // might use withRemote() here instead depending on how you are connecting I suppose
g.io("graph.kryo").read().iterate()
Note that if you are connecting remotely - it seems you are sending scripts to the Docker instance given your error - then be sure that that "graph.kryo" file path is accessible to Docker. That's what's nice about ToInputStream from Compose as it allows you to access remote sources.

MySQL connection pool in python?

I'm trying to process large amount of data using Python and maintaining processing status in MySQL. However, I'm surprised there is no standard connection pool for python-mysql (like HikariCP in Java).
I initially started with PyMySQL, things were great until the program ran for first few hours. After few hours, things started to fail. I was getting lot of errors like:
pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on '127.0.0.1' ([Errno 99] Cannot assign requested address)")
Moreover, lot of ports were stuck in TIME_WAIT state because I'm opening and closing connections too frequently because of lack of connection pooling
/d/p/950 ❯❯❯ netstat -nt | wc -l
84752
Per this and this, I tried to set tcp_fin_timeout and ip_local_port_range, but hardly anything improved.
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout
echo 15000 65000 > /proc/sys/net/ipv4/ip_local_port_range
Then I found out that MySQL provides mysql.connector which comes with pooling functionality. After doing all that performance actually deteriorated. More processes started to get failed. I'm using Python's multiprocessing module to simultaneously run 29 processes(multiprocessing.Pool picked this no by default) on a 24 core machine. Following was the code, of course I was using .my.cnf to pass all the credential to avoid committing them to git :
import mysql.connector
from mysql.connector import pooling
conn_pool = pooling.MySQLConnectionPool(pool_name="mypool1",
pool_size=pooling.CNX_POOL_MAXSIZE,
option_files=MYSQL_CONFIG,
option_groups=MYSQL_GROUP_NODE1,
allow_local_infile=True)
conn = conn_pool.get_connection()
Finally, reverted back to old code. Still using PyMySQL and though errors are less frequent it is still causing a major problem. I looked at SQLAlchemy and couldn't really found much of a documentation around pooling.
I'm wondering how's everyone else dealing with mysql-python connection pooling issue? I really believe there should be something out there so that I don't have to reinvent the wheel.
Any pointers are much appreciated.
DBUtils implements MySQL (and generally claims to support abritrary DB-API 2 compliant database interfaces) user-sized connection pool PooledDB, thead-mapped pool PersistentDB and SteadyDB (see functionality section). The latter should fit your case where multiprocessing.Pool creates worker processes with managed persistent database connection each. It is described as:
DBUtils.SteadyDB is a module implementing "hardened" connections to a database, based on ordinary connections made by any DB-API 2 database module. A "hardened" connection will transparently reopen upon access when it has been closed or the database connection has been lost or when it is used more often than an optional usage limit.
You can use it with PyMySQL like:
import pymysql
from DBUtils.SteadyDB import connect
db = connect(
creator = pymysql, # the rest keyword arguments belong to pymysql
user = 'guest', password = '', database = 'name',
autocommit = True, charset = 'utf8mb4',
cursorclass = pymysql.cursors.DictCursor)
Also see this related question for more examples.

Write to the system's standard error in Progress

I am writing a small program in Progress that needs to write an error message to the system's standard error. What ways, simple if at all possible, can I use to print to standard error?
I am using OpenEdge 11.3.
When on Windows (10.2B+) you can use .NET:
System.Console:Error:WriteLine ("This is an error message") .
together with
prowin32 2> stderr.out
Progress doesn't provide a way to write to stderr - the easiest way I can think of is to output-through an external program that takes stdin and echoes it to stderr.
You could look into LOG-MANAGER:WRITE-MESSAGE. It won't log to standard output or standard error, but to a client-specific log. This log should be monitored in any case (specifically if the client is an application server).
From the documentation:
For an interactive or batch client, the WRITE-MESSAGE( ) method writes the log entries to the log file specified by the LOGFILE-NAME attribute or the Client Logging (-clientlog) startup parameter. For WebSpeed agents and AppServer servers, the WRITE-MESSAGE() method writes the log entries to the server log file. For DataServers, the WRITE-MESSAGE() method writes the log entries to the log file specified by the DataServer Logging (-dslog) startup parameter.
LOG-MANAGER:WRITE-MESSAGE("Got here, x=" + STRING(x), "DEBUG1").
Will write this in the log:
[04/12/05#13:19:19.742-0500] P-003616 T-001984 1 4GL DEBUG1 Got here, x=5
There are quite a lot of options regarding the LOG-MANAGER system, what messages to display, where the file is placed, etc.
There is no easy way, but in Unixen you can always do something like this using OUTPUT THROUGH (untested):
output through "cat >&2" no-echo unbuffered.
Alternatively -- and this is tested -- if you just want error messages from a batch-mode program to go to standard out then
output through "tee" ...
...definitely works.

How to monitor elasticsearch using nagios

I would like to monitor elasticsearch using nagios.
Basiclly, I want to know if elasticsearch is up.
I think I can use the elasticsearch Cluster Health API (see here)
and use the 'status' that I get back (green, yellow or red), but I still don't know how to use nagios for that matter ( nagios is on one server and elasticsearc is on another server ).
Is there another way to do that?
EDIT :
I just found that - check_http_json. I think I'll try it.
After a while - I've managed to monitor elasticsearch using the nrpe.
I wanted to use the elasticsearch Cluster Health API - but I couldn't use it from another machine - due to security issues...
So, in the monitoring server I created a new service - which the check_command is check_command check_nrpe!check_elastic. And now in the remote server, where the elasticsearch is, I've editted the nrpe.cfg file with the following:
command[check_elastic]=/usr/local/nagios/libexec/check_http -H localhost -u /_cluster/health -p 9200 -w 2 -c 3 -s green
Which is allowed, since this command is run from the remote server - so no security issues here...
It works!!!
I'll still try this check_http_json command that I posted in my qeustion - but for now, my solution is good enough.
After playing around with the suggestions in this post, I wrote a simple check_elasticsearch script. It returns the status as OK, WARNING, and CRITICAL corresponding to the "status" parameter in the cluster health response ("green", "yellow", and "red" respectively).
It also grabs all the other parameters from the health page and dumps them out in the standard Nagios format.
Enjoy!
Shameless plug: https://github.com/jersten/check-es
You can use it with ZenOSS/Nagios to monitor cluster health, data indices, and individual node heap usage.
You can use this cool Python script for monitoring your Elasticsearch cluster. This script check your IP:port for Elasticsearch status. This one and more Python script for monitoring Elasticsearch can be found here.
#!/usr/bin/python
from nagioscheck import NagiosCheck, UsageError
from nagioscheck import PerformanceMetric, Status
import urllib2
import optparse
try:
import json
except ImportError:
import simplejson as json
class ESClusterHealthCheck(NagiosCheck):
def __init__(self):
NagiosCheck.__init__(self)
self.add_option('H', 'host', 'host', 'The cluster to check')
self.add_option('P', 'port', 'port', 'The ES port - defaults to 9200')
def check(self, opts, args):
host = opts.host
port = int(opts.port or '9200')
try:
response = urllib2.urlopen(r'http://%s:%d/_cluster/health'
% (host, port))
except urllib2.HTTPError, e:
raise Status('unknown', ("API failure", None,
"API failure:\n\n%s" % str(e)))
except urllib2.URLError, e:
raise Status('critical', (e.reason))
response_body = response.read()
try:
es_cluster_health = json.loads(response_body)
except ValueError:
raise Status('unknown', ("API returned nonsense",))
cluster_status = es_cluster_health['status'].lower()
if cluster_status == 'red':
raise Status("CRITICAL", "Cluster status is currently reporting as "
"Red")
elif cluster_status == 'yellow':
raise Status("WARNING", "Cluster status is currently reporting as "
"Yellow")
else:
raise Status("OK",
"Cluster status is currently reporting as Green")
if __name__ == "__main__":
ESClusterHealthCheck().run()
I wrote this a million years ago, and it might still be useful: https://github.com/radu-gheorghe/check-es
But it really depends on what you want to monitor. The above measures:
if Elasticsearch responds to HTTP
if ingestion rate drops under the defined levels
if total number of documents drops the defined levels
But of course there's much more that might be interesting. From query time to JVM heap usage. We wrote a blog post about the most important ones here: https://sematext.com/blog/top-10-elasticsearch-metrics-to-watch/
Elasticsearch has APIs for all these, so you may be able to use a generic check_http_json to get the needed metrics. Alternatively, you may want to use something like Sematext Monitoring for Elasticsearch, which gets these metrics out of the box, then forward threshold/anomaly alerts to Nagios. (disclosure: I work for Sematext)

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