Device storage consumption - android-management-api

Using the Android Management API, I'm trying to collect the device's storage consumption information.
I found some information in memoryInfo and memoryEvents.
In memoryInfo there is an attribute called "totalInternalStorage" and in "memoryEvents there is" an event of type "INTERNAL_STORAGE_MEASURED".
Questions:
Please, what does the value shown in "totalInternalStorage" mean? Does it mean the total amount of storage available?
What does the value shown in "INTERNAL_STORAGE_MEASURED" mean? Does it mean the consumed value of internal storage?
How is a "memoryEvents" fired? Can I collect this information at any time or do I have to wait for Google to do it in their time?
I took a test and collected the following information:
totalInternalStorage = 0.1 GB
memoryEvents = 4 GB (INTERNAL_STORAGE_MEASURED, 3 days ago)
This information, to me, is very confusing and that's why I need your help.
Thanks

totalInternalStorage in the memoryInfo is the measurement of the root of the total "system" partition storage
MemoryEvent returns 3 value per event eventType , createTime, and byteCount. in the test you made the value you receive is as follows
eventType - INTERNAL_STORAGE_MEASURED it means that the memory measured was the Internal Storage or read-only system partition
byteCount - 4 GB is the number of free bytes in the medium or in your internal storage
createTime - 3 days ago , it is the day where the event occurred
The memoryInfo measurements are taken asynchronously on the device either when a change is detected or when there's a periodic refresh of the device status. You can check the status everytime you call device.get()

Related

Dataflow job has high data freshness and events are dropped due to lateness

I deployed an apache beam pipeline to GCP dataflow in a DEV environment and everything worked well. Then I deployed it to production in Europe environment (to be specific - job region:europe-west1, worker location:europe-west1-d) where we get high data velocity and things started to get complicated.
I am using a session window to group events into sessions. The session key is the tenantId/visitorId and its gap is 30 minutes. I am also using a trigger to emit events every 30 seconds to release events sooner than the end of session (writing them to BigQuery).
The problem appears to happen in the EventToSession/GroupPairsByKey. In this step there are thousands of events under the droppedDueToLateness counter and the dataFreshness keeps increasing (increasing since when I deployed it). All steps before this one operates good and all steps after are affected by it, but doesn't seem to have any other problems.
I looked into some metrics and see that the EventToSession/GroupPairsByKey step is processing between 100K keys to 200K keys per second (depends on time of day), which seems quite a lot to me. The cpu utilization doesn't go over the 70% and I am using streaming engine. Number of workers most of the time is 2. Max worker memory capacity is 32GB while the max worker memory usage currently stands on 23GB. I am using e2-standard-8 machine type.
I don't have any hot keys since each session contains at most a few dozen events.
My biggest suspicious is the huge amount of keys being processed in the EventToSession/GroupPairsByKey step. But on the other, session is usually related to a single customer so google should expect handle this amount of keys to handle per second, no?
Would like to get suggestions how to solve the dataFreshness and events droppedDueToLateness issues.
Adding the piece of code that generates the sessions:
input = input.apply("SetEventTimestamp", WithTimestamps.of(event -> Instant.parse(getEventTimestamp(event))
.withAllowedTimestampSkew(new Duration(Long.MAX_VALUE)))
.apply("SetKeyForRow", WithKeys.of(event -> getSessionKey(event))).setCoder(KvCoder.of(StringUtf8Coder.of(), input.getCoder()))
.apply("CreatingWindow", Window.<KV<String, TableRow>>into(Sessions.withGapDuration(Duration.standardMinutes(30)))
.triggering(Repeatedly.forever(AfterProcessingTime.pastFirstElementInPane().plusDelayOf(Duration.standardSeconds(30))))
.discardingFiredPanes()
.withAllowedLateness(Duration.standardDays(30)))
.apply("GroupPairsByKey", GroupByKey.create())
.apply("CreateCollectionOfValuesOnly", Values.create())
.apply("FlattenTheValues", Flatten.iterables());
After doing some research I found the following:
regarding constantly increasing data freshness: as long as allowing late data to arrive a session window, that specific window will persist in memory. This means that allowing 30 days late data will keep every session for at least 30 days in memory, which obviously can over load the system. Moreover, I found we had some ever-lasting sessions by bots visiting and taking actions in websites we are monitoring. These bots can hold sessions forever which also can over load the system. The solution was decreasing allowed lateness to 2 days and use bounded sessions (look for "bounded sessions").
regarding events dropped due to lateness: these are events that on time of arrival they belong to an expired window, such window that the watermark has passed it's end (See documentation for the droppedDueToLateness here). These events are being dropped in the first GroupByKey after the session window function and can't be processed later. We didn't want to drop any late data so the solution was to check each event's timestamp before it is going to the sessions part and stream to the session part only events that won't be dropped - events that meet this condition: event_timestamp >= event_arrival_time - (gap_duration + allowed_lateness). The rest will be written to BigQuery without the session data (Apparently apache beam drops an event if the event's timestamp is before event_arrival_time - (gap_duration + allowed_lateness) even if there is a live session this event belongs to...)
p.s - in the bounded sessions part where he demonstrates how to implement a time bounded session I believe he has a bug allowing a session to grow beyond the provided max size. Once a session exceeded the max size, one can send late data that intersects this session and is prior to the session, to make the start time of the session earlier and by that expanding the session. Furthermore, once a session exceeded max size it can't be added events that belong to it but don't extend it.
In order to fix that I switched the order of the current window span and if-statement and edited the if-statement (the one checking for session max size) in the mergeWindows function in the window spanning part, so a session can't pass the max size and can only be added data that doesn't extend it beyond the max size. This is my implementation:
public void mergeWindows(MergeContext c) throws Exception {
List<IntervalWindow> sortedWindows = new ArrayList<>();
for (IntervalWindow window : c.windows()) {
sortedWindows.add(window);
}
Collections.sort(sortedWindows);
List<MergeCandidate> merges = new ArrayList<>();
MergeCandidate current = new MergeCandidate();
for (IntervalWindow window : sortedWindows) {
MergeCandidate next = new MergeCandidate(window);
if (current.intersects(window)) {
if ((current.union == null || new Duration(current.union.start(), window.end()).getMillis() <= maxSize.plus(gapDuration).getMillis())) {
current.add(window);
continue;
}
}
merges.add(current);
current = next;
}
merges.add(current);
for (MergeCandidate merge : merges) {
merge.apply(c);
}
}

How to get the real & actual storage usage of pods on Kubernetes?

Is there any straight-forward way to get the actual storage usage of pods on Kubernetes?
I've tried to do so using Prometheus, but only the amount of storage allocated to every pod is exposed, not what is really consumed by my application (pods).
I need a way to see how much storage every pod is consuming and reporting that to Prometheus or Grafana.
There is a way but it might not be a 'straight forward' one.
If pods are running in Linux you can execute:
kubectl exec -it <pod> cat /proc/1/io
It will return stats regarding the main IO processes. Here is the description of those:
rchar
-----
I/O counter: chars read
The number of bytes which this task has caused to be read from storage. This
is simply the sum of bytes which this process passed to read() and pread().
It includes things like tty IO and it is unaffected by whether or not actual
physical disk IO was required (the read might have been satisfied from
pagecache)
wchar
-----
I/O counter: chars written
The number of bytes which this task has caused, or shall cause to be written
to disk. Similar caveats apply here as with rchar.
read_bytes
----------
I/O counter: bytes read
Attempt to count the number of bytes which this process really did cause to
be fetched from the storage layer. Done at the submit_bio() level, so it is
accurate for block-backed filesystems. <please add status regarding NFS and
CIFS at a later time>
write_bytes
-----------
I/O counter: bytes written
Attempt to count the number of bytes which this process caused to be sent to
the storage layer. This is done at page-dirtying time.
You can also get info regarding disk usage of a particular container. It was already described here.
Please let me know if that helped.
this is very tricky,
prometheus is scraping some kubelet metrics and just created a grafana dashboard with below parameters and worked :
Query :
kubelet_volume_stats_used_bytes / kubelet_volume_stats_capacity_bytes * 100
grafana legend :
{{ namespace }} | {{ persistentvolumeclaim }}

Grafana dashboard panel is taking 5 to 8 seconds to load

I am using Grafana version 5.1.3 (commit: 087143285) ,InfluxDB shell version: 1.5.2 along with jmeter.
There are 13 panels. Panel is taking 5 to 8 seconds to load.
Below query is running for panel:(When I run the same query on db server it is running very fast )
SELECT mean(“startedThreads”) FROM “virtualUsers” WHERE time >= 1537865329564ms and time <= 1537867129564ms GROUP BY time(60s) fill(null);
EXPLAIN ANALYZE
execution_time: 157.341µs
planning_time: 626.44µs
total_time: 783.781µs
SELECT count(“responseTime”)/60 FROM “requestsRaw” WHERE time >= 1537865329564ms and time <= 1537867129564ms GROUP BY time(60s) fill(null)"
execution_time: 535.011µs
planning_time: 1.805892ms
total_time: 2.340903ms
Below is memory and cpu details.Influx db and Grafans are hosted on same server.
free -g
total used free shared buff/cache available
Mem: 15 3 11 0 1 12
Swap: 7 0 6
CPU(s): 2
On-line CPU(s) list: 0,1
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 1
And as per my initial understanding Grafana minimum memory requirement is 249MB.So memory is not problem for Grafana.
Please let me if you need more details.
It is odd that the query runs fast while Grafana needs a long time. Panels should be diplayed as soon as Grafana gets a response.
Since rendering is done in the Browser AFAIK this could be the bottleneck. So if your Browser runs on a Raspberry Pi 1, please try using a different computer.
It is not clear if all Panels need a long time to load or if it is just one Panel that needs a long time. You should try to find out if the loading time is related to just one Panel.
Lastly consider that all queries are sent at the same time, so making just one query to the server from CLI may not be representative. You could try to spliting the Dashboard in multiple Dashboards to improve the loading time.

Calculate Percentage From Duration Data in Graphite/Grafana

I have state change duration data between my object state in milliseconds.I am sending this data to graphite. I want to create a single stat panel which show me the percentage of the duration less than 20 seconds. How can I create it? Any idea or any similar scenario example will be useful.
myProjectName.FromStateToState.duration 10000ms
myProjectName.FromStateToState.duration 15000ms
myProjectName.FromStateToState.duration 21000ms
myProjectName.FromStateToState.duration 25000ms
myProjectName.FromStateToState.duration 30000ms
Assume for above scenario I expect my percentage should be %40. Because I have 5 duration data and 2 of them is less than 20 seconds. I am using Graphite as data source and Grafana as visualizing.
Temporary Solution
Because I couldn't get enough attention and any answer, I will add my temprorary solution to here. If I learn exact solution in the future I will post as an answer too.
Basically I created two counter like counterSuccess and counterFail. If state change duration is less than 20 seconds increase counterSuccess otherwise increase counterFail. Then get percentage of the success rate via following basic formula counterSuccess/(counterSuccess + counterFail).
Graphite commands at Grafana Panel:
A : sumSeries(myProjectName.FromStateToState.counterSuccess.count)
B : sumSeries(myProjectName.FromStateToState.counterFail.count)
C : sumSeries(#A, #B)
D : divideSeries(#A,#C)
I defined a single stat at grafana to show it as single percentage;

eBay API error : You have exceeded your maximum call limit

I have a table of eBay itemid, and for each id I want to apply a reviseitem call, but from the second call I get the following error:
You have exceeded your maximum call limit of 3000 for 5 seconds. Try back after 5 seconds.
NB: I have just 4 calls.
How can I fix this problem?
ebay count the calls per second per unique IP's. So please make sure your all calls from your application must be less than 3000 per 5 seconds. hope this would help.
I have just finished an eBay project and this error can be misleading. eBay allow a certain amount of calla a day and if you exceed that amount in one 24 hour period you can get this error. You can get this amount increased by completing an Application Check form http://go.developer.ebay.com/developers/ebay/forums-support/certification
The eBay Trading API, to which your ReviseItem call belongs, allows up to 5000 calls per 24 hour period for all applications, and up to 1.5M calls / 24hrs for "Compatible Applications", i.e. applications that have undergone a vetting process called "Compatible Application Check". More details here: https://go.developer.ebay.com/developers/ebay/ebay-api-call-limits
However, that's just the generic, "Aggregate" call limit. There are different limits for specific calls, some of which are more liberal (AddItem: 100.000 / day) and others of which are more strict (SetApplication: 50 / day) than that. Additionally, there are hourly and periodic limits.
You can find out any application's applicable limits by executing the GetApiAccessRules call:
<GetApiAccessRulesResponse xmlns="urn:ebay:apis:eBLBaseComponents">
<Timestamp>2014-12-02T13:25:43.235Z</Timestamp>
<Ack>Success</Ack>
<Version>889</Version>
<Build>E889_CORE_API6_17053919_R1</Build>
<ApiAccessRule>
<CallName>ApplicationAggregate</CallName>
<CountsTowardAggregate>true</CountsTowardAggregate>
<DailyHardLimit>5000</DailyHardLimit>
<DailySoftLimit>5000</DailySoftLimit>
<DailyUsage>10</DailyUsage>
<HourlyHardLimit>6000</HourlyHardLimit>
<HourlySoftLimit>6000</HourlySoftLimit>
<HourlyUsage>0</HourlyUsage>
<Period>-1</Period>
<PeriodicHardLimit>10000</PeriodicHardLimit>
<PeriodicSoftLimit>10000</PeriodicSoftLimit>
<PeriodicUsage>0</PeriodicUsage>
<PeriodicStartDate>2006-02-14T07:00:00.000Z</PeriodicStartDate>
<ModTime>2014-01-20T11:20:44.000Z</ModTime>
<RuleCurrentStatus>NotSet</RuleCurrentStatus>
<RuleStatus>RuleOn</RuleStatus>
</ApiAccessRule>
<ApiAccessRule>
<CallName>AddItem</CallName>
<CountsTowardAggregate>false</CountsTowardAggregate>
<DailyHardLimit>100000</DailyHardLimit>
<DailySoftLimit>100000</DailySoftLimit>
<DailyUsage>0</DailyUsage>
<HourlyHardLimit>100000</HourlyHardLimit>
<HourlySoftLimit>100000</HourlySoftLimit>
<HourlyUsage>0</HourlyUsage>
<Period>-1</Period>
<PeriodicHardLimit>0</PeriodicHardLimit>
<PeriodicSoftLimit>0</PeriodicSoftLimit>
<PeriodicUsage>0</PeriodicUsage>
<ModTime>2014-01-20T11:20:44.000Z</ModTime>
<RuleCurrentStatus>NotSet</RuleCurrentStatus>
<RuleStatus>RuleOn</RuleStatus>
</ApiAccessRule>
You can try that out four your own application by pasting an AuthToken for your application into the form at https://ebay-sdk.intradesys.com/s/9a1158154dfa42caddbd0694a4e9bdc8 and then press "Execute call".
HTH.

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