Helpful Hints

Sometimes we have handy little tips that haven’t yet made it to a documentation page. The suggestions here may be updated or moved, if there’s something you are looking for, try Quick Search.

Account details

Customer ID

When you log into Observe, your Customer ID is the subdomain of the URL you use to access Observe. Example: 123456789012.observeinc.com

System Data

The Observe system stores information about itself in the System datastream and dataset. This datastream contains many different types of observations about activity in your workspace. The Observe Usage reporting dashboards and monitors are a useful way to interact with System data.

The System dataset can also be useful for troubleshooting issues ingesting data into Observe. To investigate ingest issues, open the System dataset and filter for OBSERVATION_KIND equals ingest_error. Use the Extract from JSON tool on the FIELDS column to find error types, messages, and more useful information. For assistance with the ingest, contact your Observe Data Engineer.

OPAL

Changing a field type

Change the type of an existing field by creating a new one with the desired type. You may keep both fields or replace the existing one by giving it the same name.

colmake foo:float64(foo)

Aggregation Options

Here’s a way to pick the correct aggregation term for the task at hand:

  • If you need to align metrics by time, use align. Alignment regularizes time series data into regularly spaced bins on a grid so it can be compared with other aligned time series.

  • If you need to aggregate numbers by space, use aggregate. Aggregation computes a single numeric value for each of the points in an aligned series so that series can be compared. If you look at visualizations automatically created by the Metrics Explorer, you will often see align and aggregate used together.

  • If you need to align any type of data across time and space across the whole query window, use statsby. The statsby command aligns and aggregates in a single command. It is not accelerable.

  • If you need to align any type of data across time and space, either bucketized “for every X minutes” or across the whole query window, use timechart. The timechart command aligns and aggregates in a single command.

Customized metric aggregation

Do common metric aggregation operations with the aggregate verb:

rollup options(buckets:100), cpu_usage:metric("cpu_usage_total", rollup:"rate", type:"cumulativeCounter")
aggregate avg_cpu_usage:avg(cpu_usage), group_by(cluster_uid, node_name, cpu_id)

You can also form more advanced aggregation operations with it as well. For example, create a weighted average using the following code:

rollup options(buckets:100), cpu_usage:metric("cpu_usage_total", rollup:"rate", type:"cumulativeCounter")
colmake weight:case(
  contains(cpu_type, "expensive"), 2.0,
  contains(cpu_type, "normal"), 1.0)
aggregate avg_cpu_usage:avg(cpu_usage * weight), group_by(cluster_uid, node_name)

Filter

Comparisons

filter temperature > 60 and temperature < 80
filter temperature < 30 or temperature > 100
filter hostname="www" or (hostname="api" and user="root")
filter not severity="DEBUG"

Operators vs Functions

Construct expressions with either operators or functions. For example, these two statements are equivalent:

filter abc < 100
filter lt(abc, 100)

if_null

For example, a source error resulted in JSON data with similar values but different key names.

FIELDS
{"data":"abc123"}
{"payload":"def456"}
{"data":"ghi789"}

Use if_null to get the value from payload if there is no value for data. Note that both values must be the same type.

colmake data:if_null(string(FIELDS.data), string(FIELDS.payload))

Performance

Limit your query window to 1 hour or less while actively modeling

By default, worksheets read 4 hours of data. Depending on the input dataset, that can be a lot of data. Consider reducing the query window to 1 hour or less while actively modeling.

Create intermediate event datasets when shaping data

Where possible, create an intermediate event dataset by publishing partially shaped data as a new event dataset. Queries and further derived datasets typically have to read less data than if you create them directly on top of the original input dataset.

This technique is especially effective if the intermediate dataset applies a selective filter to the input dataset, picks only a subset of input columns, or extracts JSON paths from an input column and then drops the original column.

Avoid defining datasets directly on a Datastream dataset.

Use options(expiry) to reduce the time range read by make_resource

By default, the make_resource verb reads a large time range of input events: 24 hours. The reason for this behavior is that make_resource must compute the state of each resource at the beginning of the query time range, and, by default, it looks for events up to 24 hours in the past. Thus, a query with make_resource with a query time range of 4 hours actually reads at least 28 hours of input data.

24+ hours can be a lot of data, especially if the input dataset is a source dataset from a Datastream. Avoid defining resource datasets directly on a Datastream dataset and create a filtered intermediary instead.

Most resource types receive events much more frequently than every 24 hours. Observe recommends adding options(expiry:duration_hr(...)) to your make_resource command to reduce the lookback where appropriate.

For example, if you know that the live instances of some resource dataset receive events at least every 15 minutes, it would be appropriate to set the resource expiration to 1 hour, thereby greatly reducing the amount of data read by make_resource:

make_resource options(expiry:duration_hr(1)), col1:col1, primarykey(pk1, pk2)

Shaping data

Field name allowed characters

In most cases, field (column) names may contain any character except double quote ", period ., or colon :. Underscores are displayed as spaces in the UI.

colmake "ΔT":float64(field3)
colmake "占用率":float64(field4)
colmake "0_3µm":float64(um03)

To reference a field with non-alphanumeric characters in an OPAL statement, use double quotes and prepend @..

colmake temp_difference:@."ΔT"

Regex extracted columns (either Extract From Text or extract_regex) are limited to alphanumeric characters (A-Z, a-z, 0-9).

UI

Supported Web Browsers

Observe works best with the latest versions of Chrome, Edge, Firefox, and Safari.