Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Find the stage where data disappears before changing scrape intervals or dashboard settings. A gap can begin with target discovery, network reachability, a failed scrape, timestamp or stale-series handling, relabeling, missing instrumentation, storage, or simply a query window that does not include the samples. In Prometheus, start with the target’s up series and target status, then follow the metric through scraping, relabeling, querying, and visualization.
What a “gap” actually tells you
A dashboard showing an empty area does not by itself prove that collection stopped. The raw series may still contain samples while the panel uses a different time range, aggregation, label filter, or evaluation time. Conversely, a target can be reachable and report up=1 while one application metric is absent because the exporter or application no longer emits it.
Classify the scope before investigating:
- One series: a metric name, label value, or instrumentation path may have changed.
- Several series from one target: the exporter, endpoint, relabeling, or target process may be involved.
- An entire job: discovery, credentials, DNS, network access, or a shared configuration problem is more likely.
- One monitoring region or collector: investigate the forwarding or storage boundary rather than every target individually.
- Only one panel: first compare the panel query and time range with a direct query.
Record the metric name, complete label set, target and job, first and last observed timestamps, the dashboard’s time range, and whether another query shows the same behavior. This creates a precise incident boundary instead of treating every blank panel as a collection failure.
Follow the monitoring pipeline in order
Diagnose from the outside in. The first stage that has no evidence of success is where the investigation should concentrate.
#1 Best Overall
- Powerful Turbo Fan:CAGIWIRU Electric Air Duster have reached speed up to 130000RPM,Can efficient remove dust and debris.With LED light and Three Adjustable Speed to meet with different cleaning tasks.
- With Attached USB C Fasting Charging cable.Charing 3 hours,Enjoy up to 240 minutes of use on the lowest setting, For third speed can use for 25mins.with four charging options to meet with your needs.
- Wide Application:Upgraded attached 5 different nozzles,making it suitable for a variety of scenes, such as car,pet, pc, keyboards, and other electronic devices. It also serves for office and home clean duster.
- Handy Design & Portable:Cordless air duster electric nozzle is Light weight and small size, design and comfortable to hold and space saving, convenient to carry around. You can put it in your room or inside the car without taking up space.
- Warranty & Support: Our Electric air duster comes with 5 years warranty and 24/7 customer service. During this period, if you have any questions,pls kindly feel free to contact us.
| Pipeline stage | Evidence to check | Typical explanation for missing data | Next action |
|---|---|---|---|
| Target discovery | Expected target appears with the intended address, job, and labels | Service discovery changed, target was removed, or labels no longer match the query | Compare discovered targets with the intended inventory and current label selectors |
| Reachability | Collector can resolve and connect to the endpoint with required credentials | DNS, routing, firewall, authentication, certificate, or target availability failure | Test the path from the collector’s network boundary and inspect target status |
| Scrape | up, scrape duration, and sample counts |
Endpoint error, timeout, malformed response, or a slow or overloaded target | Use scrape diagnostics to separate connection failure from an empty or costly response |
| Relabeling and ingestion | Samples before and after metric relabeling | Rules dropped the metric or changed labels so the expected selector no longer matches | Review active relabel rules and compare sample counts |
| Storage and query | Direct query at the relevant evaluation time and range | Lookback, stale markers, explicit timestamps, or an incorrectly aligned query | Widen or shift the query deliberately and inspect the newest sample time |
| Visualization | Panel expression, variables, aggregation, and time range | Panel transformation or time window hides valid samples | Run the exact expression in the expression browser, then compare results |
Use Prometheus’s built-in scrape signals
Prometheus creates its own scrape metrics for each target. Query them directly before looking at an application metric.
| Series | What it means | How to interpret it |
|---|---|---|
up |
One when the target is healthy and reachable for the scrape; zero when the scrape fails | up=0 establishes a scrape failure, but up=1 does not establish that every expected application metric exists |
scrape_duration_seconds |
Time spent performing the scrape | A value approaching the configured timeout points toward a slow endpoint, overloaded target, or network problem |
scrape_samples_scraped |
Samples returned by the target | A sudden drop or zero can indicate exporter behavior, endpoint changes, or a response that contains fewer metrics |
scrape_samples_post_metric_relabeling |
Samples remaining after metric relabeling | A lower value than the pre-relabel count indicates that relabel rules removed samples |
For example, begin with expressions such as:
up{job="api"}
scrape_duration_seconds{job="api"}
scrape_samples_scraped{job="api"}
scrape_samples_post_metric_relabeling{job="api"}Inspect the target status page as well as these series. A target marked down with up=0 requires a reachability or scrape investigation; it is not fixed by changing a panel query.
Check discovery, endpoint, and target labels
Confirm that the target still exists
Open Prometheus’s target status view and verify that the expected target is present, not merely that its old time series remains in a query result. Compare the current address, scheme, job label, and instance label with the labels used by the dashboard. A discovery system can remove a target or replace its address while leaving the dashboard’s selector unchanged.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Check the complete endpoint path
Confirm the scheme, host, port, metrics path, and any authentication or certificate settings in the effective job configuration. A target process may be healthy on its application port while the metrics endpoint has moved, requires credentials, or is blocked from the collector’s network.
Separate target health from metric availability
up=1 means Prometheus completed a healthy scrape. It does not guarantee that a particular metric name, label, or event-specific series was returned. If only selected series are absent, continue to instrumentation and relabeling rather than repeatedly testing the network.
Rank #2
- Screen Cleaner is Your Screen’s New Bestfriend! - EVEO is proud to present a screen cleaner that’s perfectly suited for your TV. Meet your new screen cleaner, computer screen cleaner, laptop cleaner, iPad cleaner, Macbook,tv cleaner or any other electronic device. Our screen cleaner spray and wipe along with the included plush microfiber cloth, easily removes dust, fingerprints & other smudges on the screen’s surface. Clean effectively for a streak-free screen
- Gentle on your Screens - Our screen cleaner spray and wipes is compatible to be used even for the most sensitive LCD, LED, CRT, and OLED screens in proper use. Be at ease knowing that this product is compatible with all the major brands: LG, SONY, Samsung, Sharp, iPad, iPhone, Android screens, Kindle, PC monitors - we’ve got you covered! Can be used as LCD screen cleaner, tv cleaner, smart tv screen cleaner, and more
- Premium Super Soft Plush Microfiber Cloth - Included in this efficient screen cleaning kit. This screen cleaner spray and wipe has our signature plush microfiber cloth specially designed to comply with screens and monitors and leave them streak-free. Has been shown to effectively absorbs stubborn stains, zero streaks, and no fiber shedding. Always use this together with our screen cleaner for the best results
- Easy-to-Use Screen Cleaner Kit + microfiber cleaning cloth - The EVEO Screen Cleaning Kit will easily be your new favorite tool when it comes to taking care of the things you love most, quick and easy solution for a streak-free screen. Simply screw on the sprayer gun on the screen cleaner bottle. Spray the cleaning liquid onto the microfiber cloth, then wipe the screen until desired cleanliness & shine is achieved.
- Quality Screen Care Kit Worth Purchasing - Enjoy a convenient Screen Cleaner anytime, anywhere you need it. Your satisfaction is our top priority. We stand behind the quality of our products and that’s why, you shouldn’t be worrying at all. We manufacture the Best Screen Cleaner. and can be used for laptop cleaning kit, laptop screen cleaner, tv screen cleaner for smart tv. MacBook screen cleaner, monitor cleaner or screen cleaner spray for electronic devices with microfiber cleaning cloth
Verify scrape interval and timeout as deployed
Inspect the configuration that the running Prometheus process actually loaded. The Prometheus configuration reference documents a current global default scrape interval of one minute and a global scrape timeout of ten seconds, but job-level settings and deployed versions can override those values. The timeout cannot be greater than the scrape interval.
| Setting | Question | Failure pattern |
|---|---|---|
| Scrape interval | How often should this job be collected? | Gaps that repeat at a regular cadence may reflect an interval longer than the dashboard assumes, or a target that is intermittently unavailable between scrapes |
| Scrape timeout | How long may one scrape run before it fails? | Long scrape durations followed by up=0 indicate a timeout or endpoint performance issue |
| Job and target overrides | Does this job differ from the global values? | Assuming global defaults can make a valid job look misconfigured |
A Prometheus tutorial commonly demonstrates a 15-second scrape interval. That value is an example configuration, not a universal default or recommendation. Use the effective value from your deployed configuration and version.
Do not increase the timeout blindly. A longer timeout can allow a slow endpoint to finish, but it also consumes collector resources and can make failures less obvious. First measure scrape_duration_seconds, then determine whether the endpoint is slow because it performs expensive collection, is CPU-saturated, or is waiting on a dependency.
Investigate timestamps, staleness, and query timing
Understand when Prometheus stops returning a series
When a scrape or rule evaluation no longer returns a previously seen series, Prometheus can mark that series stale. Queries after the stale point return no value until new samples arrive. This behavior can look like erased data even though it is a deliberate indication that the series is no longer being produced.
Check the lookback window
Prometheus instant queries use the newest sample within a five-minute lookback period by default. If the last sample is older than that window, the query returns no value even though the sample may still exist in storage. Check the query’s evaluation time, dashboard range, and any configured lookback override. A panel evaluated just after a target stopped scraping can therefore show a blank result while a wider historical range still shows the earlier samples.
Rank #3
- 【Large size】：Measuring 800 x 300 mm/ 31. 5×12 inches, which is wider and taller than others. Large mouse pad can perfectly fit your keyboard and mouse of any size, and there is also ample space for peripherals such as phones, tablets, etc.
- 【LED backlight mouse pad】：Blade Hawks RGB mouse pad provides 7 static modes and 7 dynamic modes will give you the options you are looking for. Power-off memory function remembers the last lighting mode you selected. The super glow fiber Chroma will give you a colorful gaming setup that you want.
- 【Anti-slip rubber base】：Made from Natural rubber, this gaming mousepad will firmly grip your desktop, allowing you to enjoy the ultimate precision in the games you are most passionate about. It also comes with a texture that enhances this ability even further.
- 【Smooth and waterproof surface】: Micro-textured cloth surface, for extremely precise mouse control and a smooth movement. When liquid splashes on the gaming mouse pad, it forms water droplets and slides down. Will not delay your work or gameplay.
- 【Plug and play】: This mouse and keyboard pad is powered by USB, plug and play, no driver required. One button control light modes. Press one time to change the lighting mode, press twice to change the brightness, press and hold about 3 seconds turn ON/OFF.
Check explicit timestamps and clock alignment
Targets can expose their own sample timestamps. Prometheus configuration determines whether those timestamps are honored or ignored. If explicit timestamps are in use, compare the target’s clock with the collector and inspect whether samples are being assigned times far in the past or future. Clock drift can create apparent gaps, out-of-order behavior, or samples that fall outside the panel’s selected range.
Recommended Free Tools
When testing, run a direct query at a known evaluation time and then use a range query that spans the last confirmed sample, the suspected gap, and the first sample after recovery. This distinguishes a query-window problem from a collection interruption.
Check instrumentation and metric relabeling
Confirm that the exporter still emits the metric
If the target is reachable and the scrape returns samples, inspect the raw metrics endpoint or the target’s exporter output for the missing name. Application releases can remove a metric, rename it, alter label keys, or emit it only after a code path has executed. A selector that expects the old label set will then return nothing even though collection is functioning.
Distinguish “not observed yet” from zero
For a known series that should exist before an event occurs, exporting a default zero makes “the event has not happened” distinguishable from “the metric is not being emitted.” This is especially important for counters or state indicators that are created only when a request, error, or job first occurs. Use a zero only when zero is semantically valid; do not manufacture values for an entity that genuinely does not exist.
Review metric relabel rules
Compare scrape_samples_scraped with scrape_samples_post_metric_relabeling. If the latter falls while the former remains stable, inspect drop, keep, label-map, and label-replacement rules for the affected job. A changed label value can also move a time series to a new identity, making the old label selector appear empty.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problemsRank #4
- 【Softer and More Comfortable】Vaydeer wrist rest has unique diamond pattern, which is the combination of softness and aesthetics. The materials of wrist rest are improved into higher quality memory foam and covered with silky smooth lycra. The computer wrist rest makes you as comfortable and cushiony as like rest your wrists on clouds.
- 【Ergonomic Wrist Saver】The wrist rests for keyboard and mouse comes with a 17.32×3.15×0.83 inch keyboard wrist pad and a 5.94×3.15×0.83 inch mouse wrist support. Based on ergonomic design, the unique concave shape is the perfect fit for your wrist joints. The wrist rest pad fits most computer keyboards and laptops, improve hand and wrist posture, release your wrist and arm stress.
- 【Non-Slip Rubber Bottom】Featuring an anti-skid silicone base on the bottom, this wrist keyboard support stays firmly in place on your desk, preventing the padding from sliding around, ensuring stable and consistent wrist support during extended computer sessions.
- 【Better Experience & Pain Relief】Our keyboard arm rest is beneficial to alleviate the soreness caused by direct contact and friction between your arm and a hard desk surface, reducing the risk of wrist fatigue or carpal tunnel. The soft texture of memory foam can evenly distribute the pressure around your wrists and provide good support with just enough give.
- 【Helpful in Multiple Scenarios】Whether you're working, studying, writing, typing, gaming, this keyboard and mouse rest combo is an essential accessory to add comfort and support to your hands and wrists. It’s also a great gift for men, women, family, friend, coworker, gamer, teacher, etc.
Instrument custom collectors
Custom collectors should expose their own collection duration and error count. Those signals reveal an internal collector failure even when the HTTP endpoint remains reachable and Prometheus reports up=1. Without them, an exporter can return a technically valid response that silently omits the metrics you need.
“You should never take a
rate()of a gauge.” — Prometheus project, Instrumentation documentation.
This rule prevents a query mistake from being diagnosed as a collection gap. A gauge can rise, fall, or remain constant; use a gauge directly or apply an operation appropriate to its semantics rather than treating it as a monotonically increasing counter.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Trace network and forwarding boundaries
Every network boundary adds failure modes that are independent of the target process. For remote scrapes, agents, or forwarding paths, check the following from the component that performs the connection:
- Service discovery: the collector received the current target address and labels.
- Credentials and certificates: authentication material is present, valid, and accepted by the endpoint.
- DNS: the collector resolves the intended name and is not receiving stale or split-horizon results.
- Connectivity: routing, firewall policy, proxy behavior, and security groups permit the metrics request.
- Target availability: the process and metrics handler are running on the address actually being scraped.
- Scrape cost: CPU pressure, dependency latency, or an oversized response causes the endpoint to miss its timeout.
The Prometheus Agent Mode documentation notes that crossing network boundaries can introduce failures unrelated to an individual target and can obscure where a metric disappeared. Test each hop separately: discovery to collector, collector to target, target response to ingestion, and ingestion to the querying component.
Best Value
- 【No Drill Mounted】Cable management tray can be assembled in as little as 3 minutes or less-simply. Side clips easily clampe the edge of desk, pass through the holes on the sides, and secure excess cables with baskets. Desk cable management supports inward or outward installation to meet your needs in different scenarios, and provides you with great convenience when collecting and organizing wires.
- 【Rubber Pad Protects Desk】Wire organizer under desk built-in soft rubber pads on the clamp protect your desk from scratches, so you will not damage your furniture or office.
- 【Sturdy and Beautiful】Cord management under desk is made of high-quality carbon steel and holds about 15 lbs. The wire basket has 2 holes on each side of the tray to enable your cables to pass freely. Cable baskets are suitable for desk thickness use from 0.4" to 2.4".
- 【Space Saving & Keep Organized】Desk cable management tray holds all your power cords, outlet strips, USB hubs and computer transformers hidden from your feet, and the data cables will not enter the vacuum cleaner to keep your desk clean and tidy. Desk wire organizer is also suitable for use in the kitchen and outdoors.
- 【Reduce Safety Risks】Cable tray under desk keeps all plugs away from your kids, no more worry about tripping. Using 2 holes wire tray saves extra space, helps you easily cabling and wire protection. The mesh design is not easy to accumulate dust, but avoids safety accidents caused by messy wires.
Use this end-to-end diagnostic runbook
- Define the gap. Record the exact metric and labels, target, job, first and last observed timestamps, affected scope, and dashboard range. Run the raw expression outside the panel.
- Check target presence. In the Prometheus target view, verify the target address, scheme, job, instance, and current state. If it is absent, fix discovery or configuration before examining application instrumentation.
- Query
up. Use the same job and instance labels. A zero sends you to endpoint, credentials, DNS, network, or timeout checks; a one lets you proceed to metric-specific checks. - Measure the scrape. Query
scrape_duration_seconds,scrape_samples_scraped, andscrape_samples_post_metric_relabelingover the gap. Look for slow scrapes, zero samples, or a drop caused by relabeling. - Confirm effective configuration. Check the loaded job settings, endpoint, interval, timeout, timestamp policy, and target-discovery rules. Remember that documented global defaults may not match a job override or an older deployment.
- Check query timing. Compare the dashboard’s evaluation time and range with the newest sample. Account for the five-minute default lookback and for stale-series behavior when a scrape stops returning a series.
- Inspect the metric source. Verify the exporter or application output, metric name, labels, event gating, and custom collector error and duration metrics. Check relabel rules if raw samples exist but the queried series does not.
- Trace forwarding. For an agent or remote path, test discovery, authentication, DNS, connectivity, target availability, and each handoff independently.
- Apply the smallest repair. Correct the failed stage—such as restoring discovery, fixing credentials, repairing instrumentation, or adjusting a justified timeout—rather than changing unrelated dashboard expressions.
- Verify recovery. Confirm the target is healthy, query the expected metric and labels directly, and watch for new samples at the configured cadence. Then reload the dashboard and confirm that its panel expression produces the same result.
Common misleading fixes
Changing the dashboard time range first
A wider range can reveal historical samples, but it does not restore collection. Use it as a test for lookback, staleness, or alignment; do not treat a visible old sample as proof that current scraping works.
Raising the scrape timeout without measuring
This can hide an overloaded endpoint and increase resource use. Check duration and target performance first, and keep the timeout no greater than the interval.
Assuming up=1 proves application correctness
It proves target scrape health, not that every metric is emitted, labeled as expected, or retained after relabeling.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallUsing a rate query to test a gauge
A query can be semantically wrong even when the underlying samples are present. Validate metric type and intended behavior before declaring a data gap.
What to record for a durable fix
Close the incident with the evidence that identifies the failed stage: target address and labels, effective interval and timeout, representative up and scrape-diagnostic values, the metric’s raw output, relabeling results, query evaluation time and lookback, and any network boundary involved. Also record whether the series disappeared because of a deployment, discovery change, instrumentation condition, or target outage. This makes the next gap comparable instead of restarting the investigation from an empty dashboard.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
