docs: add section explaining force flush

The section was added as result of user's feedback. It documents beahvior of this
handler and expectations of its use.

Signed-off-by: hagen1778 <roman@victoriametrics.com>

.github/workflows/build.yml

@@ -63,11 +63,11 @@ jobs:
             arch: amd64
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
 
       - name: Setup Go
         id: go
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c  # v6.4.0
+        uses: actions/setup-go@v6
         with:
           cache-dependency-path: |
             go.sum

.github/workflows/changelog-linter.yml

@@ -9,7 +9,7 @@ jobs:
   tip-lint:
     runs-on: 'ubuntu-latest'
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+      - uses: 'actions/checkout@v6'
         with:
           # needed for proper diff
           fetch-depth: 0

.github/workflows/check-commit-signed.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0  # we need full history for commit verification
 

.github/workflows/check-licenses.yml

@@ -15,11 +15,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@master
 
       - name: Setup Go
         id: go
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c  # v6.4.0
+        uses: actions/setup-go@v6
         with:
           go-version-file: 'go.mod'
           cache: false
@@ -27,7 +27,7 @@ jobs:
       - run: go version
 
       - name: Cache Go artifacts
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae  # v5.0.5
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cache/go-build

.github/workflows/codeql-analysis-go.yml

@@ -29,18 +29,18 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
 
       - name: Set up Go
         id: go
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c  # v6.4.0
+        uses: actions/setup-go@v6
         with:
           cache: false
           go-version-file: 'go.mod'
       - run: go version
 
       - name: Cache Go artifacts
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae  # v5.0.5
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cache/go-build
@@ -50,14 +50,14 @@ jobs:
           restore-keys: go-artifacts-${{ runner.os }}-codeql-analyze-${{ steps.go.outputs.go-version }}-
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@95e58e9a2cdfd71adc6e0353d5c52f41a045d225  # v4.35.2
+        uses: github/codeql-action/init@v4.35.2
         with:
           languages: go
 
       - name: Autobuild
-        uses: github/codeql-action/autobuild@95e58e9a2cdfd71adc6e0353d5c52f41a045d225  # v4.35.2
+        uses: github/codeql-action/autobuild@v4.35.2
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@95e58e9a2cdfd71adc6e0353d5c52f41a045d225  # v4.35.2
+        uses: github/codeql-action/analyze@v4.35.2
         with:
           category: 'language:go'

.github/workflows/docs.yaml

@@ -16,19 +16,19 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
         with:
           path: __vm
 
       - name: Checkout private code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
         with:
           repository: VictoriaMetrics/vmdocs
           token: ${{ secrets.VM_BOT_GH_TOKEN }}
           path: __vm-docs
 
       - name: Import GPG key
-        uses: crazy-max/ghaction-import-gpg@2dc316deee8e90f13e1a351ab510b4d5bc0c82cd  # v7.0.0
+        uses: crazy-max/ghaction-import-gpg@v7
         id: import-gpg
         with:
           gpg_private_key: ${{ secrets.VM_BOT_GPG_PRIVATE_KEY }}

.github/workflows/test.yml

@@ -32,11 +32,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
 
       - name: Setup Go
         id: go
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c  # v6.4.0
+        uses: actions/setup-go@v6
         with:
           cache-dependency-path: |
             go.sum
@@ -47,7 +47,7 @@ jobs:
       - run: go version
 
       - name: Cache golangci-lint
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae  # v5.0.5
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cache/golangci-lint
@@ -72,11 +72,11 @@ jobs:
 
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
 
       - name: Setup Go
         id: go
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c  # v6.4.0
+        uses: actions/setup-go@v6
         with:
           cache-dependency-path: |
             go.sum
@@ -94,11 +94,11 @@ jobs:
 
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
 
       - name: Setup Go
         id: go
-        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c  # v6.4.0
+        uses: actions/setup-go@v6
         with:
           cache-dependency-path: |
             go.sum

.github/workflows/vmui.yml

@@ -32,11 +32,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Code checkout
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        uses: actions/checkout@v6
 
       - name: Cache node_modules
         id: cache
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae  # v5.0.5
+        uses: actions/cache@v5
         with:
           path: app/vmui/packages/vmui/node_modules
           key: vmui-deps-${{ runner.os }}-${{ hashFiles('app/vmui/packages/vmui/package-lock.json', 'app/vmui/Dockerfile-build') }}
@@ -69,7 +69,7 @@ jobs:
           VMUI_SKIP_INSTALL: true
 
       - name: Annotate Code Linting Results
-        uses: ataylorme/eslint-annotate-action@d57a1193d4c59cbfbf3f86c271f42612f9dbd9e9  # 3.0.0
+        uses: ataylorme/eslint-annotate-action@v3
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           report-json: app/vmui/packages/vmui/vmui-lint-report.json

docs/victoriametrics/Cluster-VictoriaMetrics.md

@@ -700,6 +700,7 @@ Also in the cluster version the `/prometheus/api/v1` endpoint ingests  `jsonl`,
 
 - `vmstorage` nodes provide the following HTTP endpoints on `8482` port:
   - `/internal/force_merge` - initiate [forced compactions](https://docs.victoriametrics.com/victoriametrics/single-server-victoriametrics/#forced-merge) on the given `vmstorage` node.
+  - `/internal/force_flush` - [flush in-memory buffers](https://docs.victoriametrics.com/victoriametrics/single-server-victoriametrics/#forced-flush) for recently ingested samples into searchable parts on the given `vmstorage` node.
   - `/snapshot/create` - create [instant snapshot](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282),
     which can be used for backups in background. Snapshots are created in `<storageDataPath>/snapshots` folder, where `<storageDataPath>` is the corresponding
     command-line flag value.

docs/victoriametrics/README.md

@@ -701,11 +701,11 @@ It's better to use the `-retentionPeriod` command-line flag for efficient prunin
 
 ## Forced merge
 
-VictoriaMetrics performs [data compactions in background](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282)
-in order to keep good performance characteristics when accepting new data. These compactions (merges) are performed independently on per-month partitions.
-This means that compactions are stopped for per-month partitions if no new data is ingested into these partitions.
-Sometimes it is necessary to trigger compactions for old partitions. For instance, in order to free up disk space occupied by [deleted time series](#how-to-delete-time-series).
-In this case forced compaction may be initiated on the specified per-month partition by sending request to `/internal/force_merge?partition_prefix=YYYY_MM`,
+VictoriaMetrics performs [data compaction in background](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282)
+to keep high performance during ingestion. These compactions (merges) are performed independently on per-month partitions.
+Partitions that don't receive new data will eventually stop merging parts, as they reach an optimal state.
+Sometimes it is necessary to trigger merges for old partitions. For example, to free up disk space occupied by [deleted time series](https://docs.victoriametrics.com/victoriametrics/#how-to-delete-time-series).
+User can **force** compaction on the specified per-month partition by sending request to `/internal/force_merge?partition_prefix=YYYY_MM`,
 where `YYYY_MM` is per-month partition name. For example, `http://victoriametrics:8428/internal/force_merge?partition_prefix=2020_08` would initiate forced
 merge for August 2020 partition. The call to `/internal/force_merge` returns immediately, while the corresponding forced merge continues running in background.
 
@@ -713,6 +713,26 @@ Forced merges may require additional CPU, disk IO and storage space resources. I
 since VictoriaMetrics automatically performs [optimal merges in background](https://medium.com/@valyala/how-victoriametrics-makes-instant-snapshots-for-multi-terabyte-time-series-data-e1f3fb0e0282)
 when new data is ingested into it.
 
+The `/internal/force_merge` endpoint can be protected from unauthorized access via `--forceMergeAuthKey` command-line flag.
+See [General security recommendations](https://docs.victoriametrics.com/victoriametrics/#general-security-recommendations) for more details.
+
+## Forced flush
+
+VictoriaMetrics puts the recently [ingested samples](https://docs.victoriametrics.com/victoriametrics/keyconcepts/#write-data) into in-memory buffers,
+which aren't available for [querying](https://docs.victoriametrics.com/victoriametrics/keyconcepts/#query-data) for up to a few seconds.
+If you need querying samples immediately after their ingestion, then call `/internal/force_flush` HTTP endpoint before querying.
+This endpoint converts in-memory buffers with the recently ingested samples into searchable data blocks.
+
+It isn't recommended requesting the `/internal/force_flush` HTTP endpoint on a regular basis, since this increases CPU usage
+and slows down data ingestion. It is expected that the `/internal/force_flush` is requested in automated tests, which need querying
+the recently ingested data.
+
+> VictoriaMetrics may intentionally hide samples with timestamps close to the current time during querying.
+> This behavior is controlled via `-search.latencyOffset` command-line flag. See more details in [Query latency](https://docs.victoriametrics.com/victoriametrics/keyconcepts/#query-latency) documentation.
+
+The `/internal/force_flush` endpoint can be protected from unauthorized access via `-forceFlushAuthKey`[command-line flag.
+See [General security recommendations](https://docs.victoriametrics.com/victoriametrics/#general-security-recommendations) for more details.
+
 ## How to export time series
 
 VictoriaMetrics provides the following handlers for exporting data:
@@ -1738,8 +1758,8 @@ VictoriaMetrics provides the following security-related command-line flags:
   with [HTTP Basic Authentication](https://en.wikipedia.org/wiki/Basic_access_authentication).
 * `-deleteAuthKey` for protecting `/api/v1/admin/tsdb/delete_series` endpoint. See [how to delete time series](#how-to-delete-time-series).
 * `-snapshotAuthKey` for protecting `/snapshot*` endpoints. See [how to work with snapshots](#how-to-work-with-snapshots).
-* `-forceFlushAuthKey` for protecting `/internal/force_flush` endpoint. See [these docs](#troubleshooting).
-* `-forceMergeAuthKey` for protecting `/internal/force_merge` endpoint. See [force merge docs](#forced-merge).
+* `-forceFlushAuthKey` for protecting `/internal/force_flush` endpoint. See [force flush docs](https://docs.victoriametrics.com/victoriametrics/single-server-victoriametrics/#forced-flush).
+* `-forceMergeAuthKey` for protecting `/internal/force_merge` endpoint. See [force merge docs](https://docs.victoriametrics.com/victoriametrics/single-server-victoriametrics/#forced-merge).
 * `-search.resetCacheAuthKey` for protecting `/internal/resetRollupResultCache` endpoint. See [backfilling](#backfilling) for more details.
 * `-reloadAuthKey` for protecting `/-/reload` endpoint, which is used for force reloading of [`-promscrape.config`](#how-to-scrape-prometheus-exporters-such-as-node-exporter).
 * `-configAuthKey` for protecting `/config` endpoint, since it may contain sensitive information such as passwords.

docs/victoriametrics/enterprise.md

@@ -353,18 +353,6 @@ Example Docker image:
 
 `victoriametrics/victoria-metrics:v1.143.0-enterprise-fips` – uses the FIPS-compatible binary and based on `scratch` image.
 
-## What Happens to Licensed Components When a License Expires
-
-When a license expires, all licensed components continue to function normally until a restart occurs.
-
-License checks happen only at startup. If a license expires while the component is running, nothing changes; the component continues to run until the next restart. 
-
-This means you don't need to restart components to install a new license. The component automatically picks up the new license the next time it restarts. The exception is when the `-license` flag is used, because the license is supplied at startup and changing it requires restarting VictoriaMetrics with the updated flag value.
-
-If your license has expired and you decide to not renew it, you can switch to the VictoriaMetrics Open Source version without data loss, as both versions share the same data model. In doing so, however, you will lose access to the [VictoriaMetrics Enterprise features](https://docs.victoriametrics.com/victoriametrics/enterprise/#victoriametrics-enterprise-features).
-
-See [updating the license key](https://docs.victoriametrics.com/victoriametrics/enterprise/#updating-the-license-key) for more details.
-
 ## Monitoring license expiration
 
 All the Enterprise components expose the following metrics at the `/metrics` page: