I'm using GAPI library (in PHP) for querying Google Analytics API.
I request 2 dimensions (pagePath, date), 2 metric (pageviews, visits), past 365 days time range, and 2 filters for pagePath. Average time to get data for one query is 25-30 sec.
When I use only 1 metric (pageviews), average response time is 3 sec.
Why would there be such a difference when using 1 or 2 metrics?
I'm guessing that the path/date/pageviews is stored pre-calculated, while the path/date/visits needs to be calculated off the data-store (be thankful you're not applying complicated segments - then it gets really slow).
There's hints about how this might work in the google BigTable paper.
Related
i run into this error in AWS cloudwatch
which does not make sense as I think/thought we had 0 high resolution metrics(high resolution only records for 3 hours). We typically just do 1 minute interval reporting. How do I find all metrics with high resolution? In this way I am hoping I can edit them to not high resolution.
I searched around a ton on the documentation and I looked into micrometer code which seems to default to highResolution = false and a step of 2 minutes. (We are using micrometer). I am trying to figure out next steps on figuring out why AWS thinks this data is high resolution data.
I was also thinking 'ok, perhaps it would roll up to 1 minute data then 5 minute data' so in my query I tried 1 minute and 5 minute but I still get the error of only 3 hours of data.
Error is thrown because you're using the query syntax (SELECT ...) and that only supports the latest 3 hours of data. The feature is called Metrics Insights, you can see the limits here: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch-metrics-insights-limits.html
Error is not related to high resolution metrics. Even if they were high resolution, when you're setting the period to 5 min, you would only retrieve datapoints aggregated to 5 min granularity.
I'm new to promQL and I am using it to create grafana dashboard to visualize various API metrics like throughput, latency etc.
For measuring latency I came across these queries being used together. Can someone explain how are they working
histogram_quantile(0.99, sum(irate(http_request_duration_seconds_bucket{path="<API Endpoint>"}[2m])*30) by (path,le))
histogram_quantile(0.95, sum(irate(http_request_duration_seconds_bucket{path="<API Endpoint>"}[2m])*30) by (path,le))
Also I want to write a query which will show me number of API calls with latency greater than 4sec. Can someone please help me there as well?
The provided queries are designed to return 99th and 95th percentiles for the http_request_duration_seconds{path="..."} metric of histogram type over requests received during the last 2 minutes (see 2m in square brackets).
Unfortunately the provided queries have some issues:
They use irate() function for calculating the per-second increase rate of every bucket defined in http_request_duration_seconds histogram. This function isn't recommended to use in general case, because it tends to return jumpy results on repeated queries - see this article for details. So it is better to use rate or increase instead when calculating histogram_quantile.
They multiply the calculated irate() by 30. This has no any effect on query results, since histogram_quantile() normalizes the provided per-bucket values.
So it is recommended to use the following query instead:
histogram_quantile(0.99,
sum(
increase(http_request_duration_seconds_bucket{path="..."}[2m])
) by (le)
)
This query works in the following way:
Prometheus selects all the time series matching the http_request_duration_seconds_bucket{path="..."} time series selector on the selected time range on the graph. These time series represent histogram buckets for the http_request_duration_seconds histogram. Each such bucket contains a counter, which counts the number of requests with duration not exceeding the value specified in the le label.
Prometheus calculates the increase over the last 2 minutes per each selected time series, e.g. how many requests hit every bucket during the last 2 minutes.
Prometheus calculates per-le sums over bucket values calculated at step 2 - see sum() function docs for details.
Prometheus calculates the estimated 99th percentile for the bucket results returned at step 3 by executing histogram_quantile function. The error of the estimation depends on the number of buckets and the le values. More buckets with better le distribution usually give lower error for the estimated percentile.
I have been exploring the Crux dataset in big query for last 10 days to extract data for data studio report. Though I consider myself good at SQL, as I have mostly worked with oracle and SQL server, I am finding it very hard to write queries against this dataset. I started from this article by Rick Viscomi, explored the queries on his github repo but still unable to figure it out.
I am trying to use the materialized table chrome-ux-report.materialized.metrics_summary to get some of the metrics but I am not sure if the Min/Avg/Max lcp (in milliseconds) for a time period (month for example) could be extracted from this table. What other queries could I possibly try which requires less data processing. (Some of the queries that I tried expired my free TB of data processing on big query).
Any suggestion, advise solution, queries are more than welcome since the documentation about the structure of the dataset and queries against it is not very clear.
For details about the fields used on the report you can check on the main documentation for the chrome ux report specially on the last part with data format which shows the dimensions and how its interpreted as show below:
Dimension
origin "https://example.com"
effective_connection_type.name 4G
form_factor.name "phone"
first_paint.histogram.start 1000
first_paint.histogram.end 1200
first_paint.histogram.density 0.123
For example, the above shows a sample record from the Chrome User Experience Report, which indicates that 12.3% of page loads had a “first paint time” measurement in the range of 1000-1200 milliseconds when loading “http://example.com” on a “phone” device over a ”4G”-like connection. To obtain a cumulative value of users experiencing a first paint time below 1200 milliseconds, you can add up all records whose histogram’s “end” value is less than or equal to 1200.
For the metrics, in the initial link there is a section called methodology where you can get information about the metrics and dimensions of the report. I recommend going to the actual origin source table per country and per site and not the summary as the data you are looking for can be obtained there. In the Bigquery part of the documentation you will find samples of how to query those tables. I find this relatable:
SELECT
SUM(bin.density) AS density
FROM
`chrome-ux-report.chrome_ux_report.201710`,
UNNEST(first_contentful_paint.histogram.bin) AS bin
WHERE
bin.start < 1000 AND
origin = 'http://example.com'
In the example above we’re adding all of the density values in the FCP histogram for “http://example.com” where the FCP bin’s start value is less than 1000 ms. The result is 0.7537, which indicates that ~75.4% of page loads experience the FCP in under a second.
About query estimation cost, you can see estimating query cost guide on google official bigquery documentation. But using this tables due to its nature consumes a lot of processing so filter it as much as possible.
In Google Dataflow, i have a job that basically looks like this:
Dataset: 100 rows, 1 column.
Recipe: 0 steps
Output: New Table.
But it takes between 6-8 minutes to run. What could be the issue?
Usually times are in minutes, not in seconds for Dataprep/dataflow setup.
These solutions are for large data sets and the duration stays constant even if you have 10 times the size.
DataPrep creates for you a DataFlow workflow, and provisions a few VMs for you, that takes time, usually that phase could be in the minute mark. And only a bit later is scaling that up to 50 or 1000 boxes.
Looking for some advice on how best to architect/design and build our pipeline.
After some initial testing, we're not getting the results that we were expecting. Maybe we're just doing something stupid, or our expectations are too high.
Our data/workflow:
Google DFP writes our adserver logs (CSV compressed) directly to GCS (hourly).
A day's worth of these logs has in the region of 30-70 million records, and about 1.5-2 billion for the month.
Perform transformation on 2 of the fields, and write the row to BigQuery.
The transformation involves performing 3 REGEX operations (due to increase to 50 operations) on 2 of the fields, which produces new fields/columns.
What we've got running so far:
Built a pipeline that reads the files from GCS for a day (31.3m), and uses a ParDo to perform the transformation (we thought we'd start with just a day, but our requirements are to process months & years too).
DoFn input is a String, and its output is a BigQuery TableRow.
The pipeline is executed in the cloud with instance type "n1-standard-1" (1vCPU), as we think 1 vCPU per worker is adequate given that the transformation is not overly complex, nor CPU intensive i.e. just a mapping of Strings to Strings.
We've run the job using a few different worker configurations to see how it performs:
5 workers (5 vCPUs) took ~17 mins
5 workers (10 vCPUs) took ~16 mins (in this run we bumped up the instance to "n1-standard-2" to get double the cores to see if it improved performance)
50 min and 100 max workers with autoscale set to "BASIC" (50-100 vCPUs) took ~13 mins
100 min and 150 max workers with autoscale set to "BASIC" (100-150 vCPUs) took ~14 mins
Would those times be in line with what you would expect for our use case and pipeline?
You can also write the output to files and then load it into BigQuery using command line/console. You'd probably save some dollars of instance's uptime. This is what I've been doing after running into issues with Dataflow/BigQuery interface. Also from my experience there is some overhead bringing instances up and tearing them down (could be 3-5 minutes). Do you include this time in your measurements as well?
BigQuery has a write limit of 100,000 rows per second per table OR 6M/per minute. At 31M rows of input that would take ~ 5 minutes of just flat out writes. When you add back the discrete processing time per element & then the synchronization time (read from GCS->dispatch->...) of the graph this looks about right.
We are working on a table sharding model so you can write across a set of tables and then use table wildcards within BigQuery to aggregate across the tables (common model for typical BigQuery streaming use case). I know the BigQuery folks are also looking at increased table streaming limits, but nothing official to share.
Net-net increasing instances is not going to get you much more throughput right now.
Another approach - in the mean time while we work on improving the BigQuery sync - would be to shard your reads using pattern matching via TextIO and then run X separate pipelines targeting X number of tables. Might be a fun experiment. :-)
Make sense?