I need to analyse one http event value which should not be greater than 30mins. & 95% event should belong to this bucket. If it fails send the alert.
My first concern is to get the right metrics in /actuator/prometheus
Steps I took:
As in every http request event, I am getting one integer value called eventMinute.
Using micrometer MeterRegistry, I tried below code
// MeterRegistry meterRegistry ...
meterRegistry.summary("MINUTES_ANALYSIS", tags);
where tag = EVENT_MINUTE which receives some integer value in each
http event.
But this way, it floods the metrics due to millions of event.
Guide me a way please, i am beginner to this. Thanks!!
The simplest solution (which I would recommend you start with) would be to just create 2 counters:
int theThing = //getTheThing()
if(theThing > 30) {
meterRegistry.counter("my.request.counter.abovethreshold").inc()
}
meterRegistry.counter("my.request.counter.total").inc()
You would increment the counter that matches your threshold and another that tracks all requests (or reuse another meter that does that for you).
Then it is simple to setup a chart or alarm:
my_request_counter_abovethreshold/my_request_counter_total < .95
(I didn't test the code. It might need a tiny bit of tweaking)
You'll be able to do a similar thing with DistributionSummary by setting various SLOs (I'm not familiar with them to be able to offer one), but start with something simple first and if it is sufficient, you won't need the other complexity.
There are certain ways to solve this problem
1 ; here is a function which receives tags, name of metrics and a value
public void createOrUpdateHistogram(String metricName, Map<String, String> stringTags, double numericValue)
{
DistributionSummary.builder(metricName)
.tags(tags)
//can enforce slo if required
.publishPercentileHistogram()
.minimumExpectedValue(1.0D) // can take this based on how you want your distibution
.maximumExpectedValue(30.0D)
.register(this.meterRegistry)
.record(numericValue);
}
then it produce metrics like
delta_bucket{mode="CURRENT",le="30.0",} 11.0
delta_bucket{mode="CURRENT", le="+Inf",} 11.0
so as infinte also hold the less than value, so subtract the le=30 from le=+Inf
Another ways could be
public void createOrUpdateHistogram(String metricName, Map<String, String> stringTags, double numericValue)
{
Timer.builder(metricName)
.tags(tags)
.publishPercentiles(new double[]{0.5D, 0.95D})
.publishPercentileHistogram()
.serviceLevelObjectives(new Duration[]{Duration.ofMinutes(30L)})
.minimumExpectedValue(Duration.ofMinutes(30L))
.maximumExpectedValue(Duration.ofMinutes(30L))
.register(this.meterRegistry)
.record((long)timeDifference, TimeUnit.MINUTES);
}
it will only have two le, the given time and +inf
it can be change based on our requirements also it gives us quantile.
I have a list of accounts and perform a hashjoin on ticks and return the accounts with ticks data. But after hashjoin I have drainTo lListJet and then read it with DistributedStream and return it.
public List<Account> populateTicksInAccounts(List<Account> accounts) {
...
...
Pipeline p = Pipeline.create();
BatchSource<Tick> ticksSource = Sources.list(TICKS_LIST_NAME);
BatchSource<Account> accountSource = Sources.fromProcessor(AccountProcessor.of(accounts));
p.drawFrom(ticksSource)
.hashJoin(p.drawFrom(accountSource), JoinClause.joinMapEntries(Tick::getTicker), accountMapper())
.drainTo(Sinks.list(TEMP_LIST));
jet.newJob(p).join();
IListJet<Account> list = jet.getList(TEMP_LIST);
return DistributedStream.fromList(list).collect(DistributedCollectors.toIList());
}
Is it possible to drainTo to java List instead of lListJet after performing a hashjoin?
Something like below is possible?
IListJet<Account> accountWithTicks = new ArrayList<>();
p.drawFrom(ticksSource)
.hashJoin(p.drawFrom(accountSource), JoinClause.joinMapEntries(Tick::getTicker), accountMapper())
.drainTo(<CustomSinkProcessor(accountWithTicks)>);
return accountWithTicks;
where in CustomSinkProcessor will take empty java list and return with the accounts?
Keep in mind that the code you submit to Jet for execution runs outside the process where you submit it from. While it would be theoretically possible to provide the API you're asking for, under the hood it would just have to perform some tricks to run the code on each member of the cluster, let all members send their results to one place, and fill up a list to return to you. It would go against the nature of distributed computing.
If you think it will help the readability of your code, you can write a helper method such as this:
public <T, R> List<R> drainToList(GeneralStage<T> stage) {
String tmpListName = randomListName();
SinkStage sinkStage = stage.drainTo(Sinks.list(tmpListName));
IListJet<R> tmpList = jet.getList(tmpListName);
try {
jet.newJob(sinkStage.getPipeline()).join();
return new ArrayList<>(tmpList);
} finally {
tmpList.destroy();
}
}
Especially note the line
return new ArrayList<>(tmpList);
as opposed to your
IListJet<Account> list = jet.getList(TEMP_LIST);
return DistributedStream.fromList(list).collect(DistributedCollectors.toIList());
This just copies one Hazelcast list to another one and returns a handle to it. Now you have leaked two lists in the Jet cluster. They don't automatically disappear when you stop using them.
Even the code I provided can still be leaky. The JVM process that runs it can die during Job.join() without reaching finally. Then the temporary list lingers on.
No, it's not, due to the distributed nature of Jet. The sink will execute in multiple parallel processors (workers). It can't add to plain Collection. The sink has to be able to insert items on multiple cluster members.
I have a website that I need to perform a Load Test on. I tried this with one user logging in and clicking around then logging out. It worked ok but now I need to try with 50 users. Initial user count is 5, increasing by 5 every 20 seconds up to a max user count of 50.
Sessions are managed so I need 50 unique logins, I do have a set of users with associated passwords. I tried doing some searching and I cannot figure out how to get the test to run with the set of users that I have.
Anyone on here have any experience with it?
Here's some helpful information considering your question: https://msdn.microsoft.com/en-us/library/dn250793.aspx
It's about using load testing in Visual Studio Ultimate to find performance issues before you release your app.
In Visual Studio Ultimate Trial version, the virtual user count is limited to 250.
If you want to use exactly as many virtual users as you have user accounts in your test data, you could use a web test plugin like this:
using Microsoft.VisualStudio.TestTools.WebTesting;
using System.ComponentModel;
namespace Plugins
{
[DisplayName("Lock Data Table Row to Virtual User Id")]
[Description("Makes each virtual user use the same data row as their user id. "
+ "Only works on first table of first data source. \r\n"
+ "LoadTest > Scenario > Percentage of New Users must be set to 0.")]
public class LockDataTableRowToVirtualUserIdWebTestPlugin : WebTestPlugin
{
public override void PreWebTest(object sender, PreWebTestEventArgs e)
{
int id = e.WebTest.Context.WebTestUserId;
// correct discrepancy (WebTests start at id 1, LoadTests start at id 0)
if (!e.WebTest.Context.ContainsKey("$LoadTestUserContext")) id -= 1;
int rows = e.WebTest.GetDataTableRowCount(e.WebTest.DataSources[0].Name, e.WebTest.DataSources[0].Tables[0].Name);
if (id > rows - 1) // not enough rows
throw new WebTestException("Not enough rows to provide all users with unique data; id=" + id + " rows=" + rows);
e.WebTest.MoveDataTableCursor(e.WebTest.DataSources[0].Name, e.WebTest.DataSources[0].Tables[0].Name, id);
}
}
}
Requires "Percentage of New Users" setting in the Load Test Scenario properties be set to 0, which keeps the virtual user ids constant for each virtual user. Otherwise, new virtual users will get new ids that exceed the data rows.
Could easily be enhanced to work on named DataSources/DataTables via properties.
In a portlet running on a websphere 7 portal server I want to create a new user group that is a subgroup of an existing group.
Here is the code (that I shortend as much as possible to keep the focus):
/* vars */
final PumaController controller = ...;
final PumaLocator locator = ...;
final PumaProfile pumeProfile = ...;
final groupCn = ... ;
/* code to add group */
final List<Group> parent = locator.findGroupsByAttribute("cn", CN_OF_GROUP);
final String parentDn = pumaProfile.getIdentifier(parent.get(0));
log.debug("creating new group with cn=" + groupCn + ", parentDn=" + parentDn);
newGroup = controller.createGroup(groupCn, parentDn, new HashMap<String, Object>(0));
The debug statement prints:
creating new group with
cn=[groupCn],
parentDn=cn=[CN_OF_GROUP],o=defaultWIMFileBasedRealm
The code DOES create a group. But it looks like the parentDN argument is ignored. The group is not created as a subgroup of parent, but it is created as a top level group. (Which is the same thing that happens if I pass null as parentDn).
What am I doing wrong here?
Probably nothing. I would raise a PMR if I were you.
If you configured federated security instead of standalone security please delete the file based realm by the way. You should always delete it when configuring federated security.
I want to process some data. I have about 25k items in a Dictionary. IN a foreach loop, I query a database to get results on that item. They're added as value to the Dictionary.
foreach (KeyValuePair<string, Type> pair in allPeople)
{
MySqlCommand comd = new MySqlCommand("SELECT * FROM `logs` WHERE IP = '" + pair.Key + "' GROUP BY src", con);
MySqlDataReader reader2 = comd.ExecuteReader();
Dictionary<string, Dictionary<int, Log>> allViews = new Dictionary<string, Dictionary<int, Log>>();
while (reader2.Read())
{
if (!allViews.ContainsKey(reader2.GetString("src")))
{
allViews.Add(reader2.GetString("src"), reader2.GetInt32("time"));
}
}
reader2.Close();
reader2.Dispose();
allPeople[pair.Key].View = allViews;
}
I was hoping to be able to do this faster by multi-threading. I have 8 threads available, and CPU usage is about 13%. I just don't know if it will work because it's relying on the MySQL server. On the other hand, maybe 8 threads would open 8 DB connections, and so be faster.
Anyway, if multi-threading would help in my case, how? o.O I've never worked with (multiple) threads, so any help would be great :D
MySqlDataReader is stateful - you call Read() on it and it moves to the next row, so each thread needs their own reader, and you need to concoct a query so they get different values. That might not be too hard, as you naturally have many queries with different values of pair.Key.
You also need to either have a temp dictionary per thread, and then merge them, or use a lock to prevent concurrent modification of the dictionary.
The above assumes that MySQL will allow a single connection to perform concurrent queries; otherwise you may need multiple connections too.
First though, I'd see what happens if you only ask the database for the data you need ("SELECT src,time FROMlogsWHERE IP = '" + pair.Key + "' GROUP BY src") and use GetString(0) and GetInt32(1) instead of using the names to look up the src and time; also only get the values once from the result.
I'm also not sure on the logic - you are not ordering the log events by time, so which one is the first returned (and so is stored in the dictionary) could be any of them.
Something like this logic - where each of N threads only operates on the Nth pair, each thread has its own reader, and nothing actually changes allPeople, only the properties of the values in allPeople:
private void RunSubQuery(Dictionary<string, Type> allPeople, MySqlConnection con, int threadNumber, int threadCount)
{
int hoppity = 0; // used to hop over the keys not processed by this thread
foreach (var pair in allPeople)
{
// each of the (threadCount) threads only processes the (threadCount)th key
if ((hoppity % threadCount) == threadNumber)
{
// you may need con per thread, or it might be that you can share con; I don't know
MySqlCommand comd = new MySqlCommand("SELECT src,time FROM `logs` WHERE IP = '" + pair.Key + "' GROUP BY src", con);
using (MySqlDataReader reader = comd.ExecuteReader())
{
var allViews = new Dictionary<string, Dictionary<int, Log>>();
while (reader.Read())
{
string src = reader.GetString(0);
int time = reader.GetInt32(1);
// do whatever to allViews with src and time
}
// no thread will be modifying the same pair.Value, so this is safe
pair.Value.View = allViews;
}
}
++hoppity;
}
}
This isn't tested - I don't have MySQL on this machine, nor do I have your database and the other types you're using. It's also rather procedural (kind of how you would do it in Fortran with OpenMPI) rather than wrapping everything up in task objects.
You could launch threads for this like so:
void RunQuery(Dictionary<string, Type> allPeople, MySqlConnection connection)
{
lock (allPeople)
{
const int threadCount = 8; // the number of threads
// if it takes 18 seconds currently and you're not at .net 4 yet, then you may as well create
// the threads here as any saving of using a pool will not matter against 18 seconds
//
// it could be more efficient to use a pool so that each thread takes a pair off of
// a queue, as doing it this way means that each thread has the same number of pairs to process,
// and some pairs might take longer than others
Thread[] threads = new Thread[threadCount];
for (int threadNumber = 0; threadNumber < threadCount; ++threadNumber)
{
threads[threadNumber] = new Thread(new ThreadStart(() => RunSubQuery(allPeople, connection, threadNumber, threadCount)));
threads[threadNumber].Start();
}
// wait for all threads to finish
for (int threadNumber = 0; threadNumber < threadCount; ++threadNumber)
{
threads[threadNumber].Join();
}
}
}
The extra lock held on allPeople is done so that there is a write barrier after all the threads return; I'm not quite sure if it's needed. Any object would do.
Nothing in this guarantees any performance gain - it might be that the MySQL libraries are single threaded, but the server certainly can handle multiple connections. Measure with various numbers of threads.
If you're using .net 4, then you don't have to mess around creating the threads or skipping the items you aren't working on:
// this time using .net 4 parallel; assumes that connection is thread safe
static void RunQuery(Dictionary<string, Type> allPeople, MySqlConnection connection)
{
Parallel.ForEach(allPeople, pair => RunPairQuery(pair, connection));
}
private static void RunPairQuery(KeyValuePair<string, Type> pair, MySqlConnection connection)
{
MySqlCommand comd = new MySqlCommand("SELECT src,time FROM `logs` WHERE IP = '" + pair.Key + "' GROUP BY src", connection);
using (MySqlDataReader reader = comd.ExecuteReader())
{
var allViews = new Dictionary<string, Dictionary<int, Log>>();
while (reader.Read())
{
string src = reader.GetString(0);
int time = reader.GetInt32(1);
// do whatever to allViews with src and time
}
// no iteration will be modifying the same pair.Value, so this is safe
pair.Value.View = allViews;
}
}
The biggest problem that comes to mind is that you are going to use multithreading to add values to a dictionary, which isn't thread safe.
You'll have to do something like this to make it work, and you might not get that much of a benefit from implementing it this was as it still has to lock the dictionary object to add a value.
Assumptions:
There is a table People in your
database
There are alot of people in
your database
Each database query adds overhead you are doing one db query for each of the people in your database I would suggest it was faster to get all the data back in one query then to make repeated calles
select l.ip,l.time,l.src
from logs l, people p
where l.ip = p.ip
group by l.ip, l.src
Try this with a loop in a single thread, I belive this will be much faster then your existing code.
With in your existing code another thing you can do is to take the creation of the MySqlCommand out of the loop, prepare it in advance and just change the parameter. This should speed up execution of the SQL. see http://dev.mysql.com/doc/refman/5.0/es/connector-net-examples-mysqlcommand.html#connector-net-examples-mysqlcommand-prepare
MySqlCommand comd = new MySqlCommand("SELECT * FROM `logs` WHERE IP = ?key GROUP BY src", con);
comd.prepare();
comd.Parameters.Add("?key","example");
foreach (KeyValuePair<string, Type> pair in allPeople)
{
comd.Parameters[0].Value = pair.Key;
If you are using mutiple threads, each thread will still need there own Command, at lest in MS-SQL this would still be faster even if you recreated and prepared the statment every time, due to the ability for the SQL server to be able to cache the execution plan of a paramertirised statment.
Before you do anything else, find out exactly where the time is being spent. Check the execution plan of the query. The first thing I'd suspect is a missing index on logs.IP.
18 minutes for something like this seems much too long to me. Even if you can cut the execution time in eight by adding more threads (which is unlikely!) you still end up using more than 2 minutes. You could probably read the whole 25k rows into memory in less than five seconds and do the necessary processing in memory...
EDIT: Just to clarify, I'm not advocating actually doing this in memory, just saying that it looks like there's a bigger bottleneck here that can be removed.
I think if you are running this on a multi core machine you could gain benefits from multi threading.
However the way I would approach it is to first look at unblocking the thread you are currently using by making asynchronous database calls. The call backs will execute on background threads, so you will get some multi core benefit there and you won't be blocking threads waiting for the db to come back.
For IO intensive apps like this example sounds like you are likely to see improved throughput depending on what load the db can handle. Assuming the db scales to handle more than one concurrent request you should be good.
Thanks everyone for your help. Currently I am using this
for (int i = 0; i < 8; i++)
{
ThreadPool.QueueUserWorkItem(addDistinctScres, i);
}
ThreadPool to run all the threads. I use the method provided by Pete Kirkham, and I'm creating a new connection per thread.
Times went down to 4 minutes.
Next I'll make something wait for the callback of the threadpool? before performing other functions.
I think the bottleneck now is the MySQL server, because the CPU usage has drops.
#odd parity I thought about that, but the real thing is waaay more than 25k rows. Idk if that'd work.
This sound like the perfect job for map/reduce, i am not a .Net-programmer, but this seems like a reasonable guide:
http://ox.no/posts/minimalistic-mapreduce-in-net-4-0-with-the-new-task-parallel-library-tpl