* fix(restore): reject SELECT restore and keep typed S3 errors
RestoreObject accepted `Type=SELECT` requests, but the restore path can
only write the retrieved bytes back to the source key: `put_restore_opts`
built SELECT output options and `restore_transitioned_object` then PUT
them over the source bucket/object. On an unversioned bucket that dropped
`x-amz-restore`, user metadata and tags from the live object; on a
versioned bucket it published a bogus latest version. Nothing was ever
written to `OutputLocation.S3`, yet the response still carried a
fabricated `x-amz-restore-output-path`.
Reject SELECT at the API boundary with a typed NotImplemented, before any
guard or metadata write, and fail closed in `put_restore_opts` as the
backstop for any other caller.
Every other RestoreObject failure was collapsed into a `Custom` error
code, which serializes as a generic retryable 500: a missing key or
version, a malformed version-id, an object that was never transitioned,
an illegal `Days`, and authorization or storage failures all looked the
same to a client. Map them to their S3 identities instead — NoSuchKey,
NoSuchVersion, InvalidArgument, InvalidObjectState, InvalidRequest,
MalformedXML — by preserving `StorageError` through `post_restore_opts`
and letting `ApiError` do the mapping. The intentional 409
RestoreAlreadyInProgress and 503 SlowDown behaviour is unchanged, and
request validation now runs before any lock is taken.
backlog#1341, backlog#2205
* test(restore): give the typed-error regression the ecstore test stack
`execute_restore_object_maps_failures_to_typed_s3_errors` builds a real
ECStore fixture, and under nextest each test runs in a spawned thread with
libtest's 2 MiB stack. On Linux CI that overflowed: the test aborted with
SIGABRT / "fatal runtime error: stack overflow" while every other test in
the run passed.
Add it to the `ecstore-base-stack` filter in both the default and ci
profiles, alongside the other `package(rustfs)` tests that drive the same
store fixture. 4 MiB matches what the deeper multipart and access
roundtrips already use.
`GET /v3/tier-stats` answered from whichever process received the
request, returning that node's rolling 24-hour transition counters as
if they were cluster totals, and the `TierRequestsSuccess` and
`TierRequestsFailure` metric names had no producer at all.
The body now separates the two quantities a tier carries. Stored
inventory comes from the persisted scanner usage snapshot, which is
already cluster-wide; rolling activity is summed over every member
through a new read-only `TierDailyStats` peer RPC. Rings are merged
rather than added, so an idle node's expired hours age out, and each
node counts only its own committed transitions, so a retry is counted
once. Coverage travels with the numbers: `activity.status` names the
reporting members and the ones that could not be asked, timed out, or
answered with a ring this build refuses to merge, and per-tier
inventory is absent rather than zero when the snapshot has no
accounting. The version 1 body stays reachable at `?format=legacy`.
Tier request counters are recorded at the two seams every remote
request passes through, so a new provider is counted by construction,
with a closed operation/outcome label set that can never grow a tier
name, endpoint or object key.
Closesrustfs/backlog#2207
Co-authored-by: cxymds <cxymds@gmail.com>
* feat(odm): merge the source listing into ListObjectsV2
Adds policy.list_through: ListObjectsV2 merges the local and source
listings into one ordered page so clients see the whole namespace during
an on-demand migration. Local entries win a key both sides hold,
CommonPrefixes are unioned under a delimiter, and the continuation token
is an opaque versioned envelope carrying both cursors.
A source listing failure or an open breaker follows policy.source_error:
propagate answers 424, not_found answers from local state and marks the
response x-rustfs-on-demand-migration-list: local_only. Source listings
are capped at 10 per second per bucket.
* test(odm): refresh the e2e-full darwin selection digest
The list-through e2e module adds seven cases to the merge lane.
* fix(odm): declare the remote client retry policy per consumer
The SDK retry policy was an inherited default: one logical call could cost
three wire requests, so the migration breaker counted logical calls on top
of a threefold amplification against a source that was already failing.
Make it an explicit RemoteS3EndpointSpec field. Replication targets declare
today's standard three attempts and keep their behaviour; the on-demand
migration source and its admin probe declare a disabled policy, so one
counted failure is exactly one source request and pull.rs owns the only
retry budget.
* fix(odm): count a stalled inline source as a source timeout
The inline tee wraps its source body in the idle guard, but the tee turns a
stalled source into an ordinary body read error, so the write-back reported
it as a local write failure. Hand commit_inline the guard so the pull is
counted under source_timeout instead.
The background pump now enforces the idle budget through the same guard
rather than a second copy of the timeout loop.
* test(odm): cover a stalled source body end to end
The fake target can now deliver a GetObject body in slices with a pause
between them, so the inline abort can be driven by a stalled source instead
of a truncated one. Two fault cases drop the workarounds they carried for
the SDK's retries: the scripted fault count and the observed source request
count now have to agree.
The operations guide records the retry and idle-timeout guarantees.
The scenario keeps the shared gating ECStore, a live RestoreObject
authorization hook and the RestoreObject usecase future alive at once, which
left the 2 MiB test-thread stack a few KiB from overflowing on Linux; pinning a
single future was not enough. Run the whole scenario through the existing
run_large_stack_test helper instead.
* feat(odm): enable on-demand migration by default
The module switch RUSTFS_ON_DEMAND_MIGRATION_ENABLED now defaults to true,
so the feature is reachable without an opt-in; setting it to false still
keeps the module out of the read path entirely. A bucket without an
on-demand-migration.json is never resolved by the runtime and makes no
source call, so the flip changes nothing for unconfigured buckets.
The admin plane now reads the switch through the predicate published by
module_switches.rs instead of its own duplicated env constant; the
behaviour (an environment read per call) is unchanged.
* test(e2e): wire three on-demand migration cases into e2e-smoke
The PR smoke lane gains one case per user-visible contract: a GET miss
that pulls and persists, a HEAD miss that answers from the source and
stores nothing, and the admin config/status pair that must redact the
source secret. The HEAD case did not exist outside the nightly
real-source lane, so it is added to get_basic_test.
Measured on darwin: the lane goes from 168 tests in 101.98 s to 171
tests in 101.92 s, since the three cases overlap the lane's existing
work. The darwin selection digests for e2e-smoke and e2e-full are
regenerated; the e2e-full linux digest still needs a Linux runner.
* docs(changelog): record the on-demand migration feature
* fix(ecstore): stop scan_dir emitting entries past a limit hit inside a subdirectory
scan_dir's flush loop recurses into a pending subdirectory when the
current sibling entry's page limit is reached mid-recursion, but kept
writing the current (later-sorting) entry regardless. gather_results
then builds the next page's continuation marker from that later entry,
which permanently skips the still-unscanned tail of the subdirectory
on resume instead of just deferring it to the next page.
Add a limit re-check right after the flush loop, before the current
entry is written, so scan_dir stops cleanly at the true last-written
key. Reproduces and fixes the rc.5 recursive ListObjectsV2 data-loss
report (7826/7881 keys, contiguous 55-key block silently dropped).
Adds scan_dir_does_not_emit_entries_past_a_limit_hit_inside_a_subdirectory.
* fix(ecstore): re-check the page limit on every dir_stack flush iteration
The flush loop that drains dir_stack can pop and recurse into more than
one pending subdirectory per outer iteration (whenever more than one
stack entry sorts below the current sibling entry). The limit re-check
added in the previous commit only ran once, after the whole flush loop
exited - so if the first recursive scan_dir call already exhausted the
page limit, the loop's next pop+recurse still went ahead and scanned
(and emitted entries for) another subdirectory beyond where the page
was supposed to stop.
Confirmed against production data: a bucket with ~1.17M objects under
one prefix still cut a recursive ListObjectsV2 listing short (825 of an
expected much larger next page, IsTruncated=false) even with the first
fix deployed, at a two-level-nested subdirectory. Move the check inside
the while loop so it runs before every pop, not just once after.
---------
Co-authored-by: Claude Agent <agent@local>
* feat(ecstore): add on-demand migration backfill job core
Add the background backfill job for on-demand migration
(rustfs/backlog#2159): a durable checkpoint under
buckets/<bucket>/on-demand-migration-backfill.json saved by If-Match
compare-and-set every 1000 keys or 10 s, a 60 s owner lease renewed by
every save, a recovery pass that takes over expired leases (or jobs this
node owned before a restart) and cancels jobs whose config changed, and a
main loop over the source ListObjectsV2 pages with the skip_existing
policy, dry runs, bounded outstanding pulls and wait-on-full enqueueing.
The pull queue gains per-job completion reports so the job can count
pulled/failed keys (hashes only), and pull permits become two-tier so an
online miss is never queued behind a backfill pull.
* feat(admin): expose on-demand migration backfill job
Wire the ODM-12 backfill job (rustfs/backlog#2159) to its operators:
POST /v3/on-demand-migration/{bucket}/backfill?op=start|cancel and
GET .../backfill return the checkpoint document, GET .../status gains a
backfill summary, and the recovery loop plus the process-wide runner are
installed at startup. Backfill control reuses
Set/GetBucketOnDemandMigrationAction and is recorded in the route policy,
the registration matrix and the admin route snapshot.
Add the rustfs-madmin wire types and client methods with golden fixtures
shared by the server tests, the backfill_* metric descriptors and their
collector, and three e2e scenarios: a full backfill across list pages,
cancellation, and resuming from the persisted continuation token after a
server restart.
feat(rustfs): serve GET misses from the migration source
Wire the on-demand migration read-through into the GET path, after the
local read and the replication proxy have both missed (rustfs/backlog#2156).
A source HEAD supplies size, validators and metadata. Conditional headers
are evaluated locally against it and never forwarded, so a source 304/412
cannot be mistaken for a source failure. An object within inline_max_bytes
is teed: the primary streams to the client while the secondary commits the
local copy in a background task, so a client disconnect still stores the
whole object and a failed write-back never touches the client stream.
Range reads and larger objects stream straight through and queue a
background pull per policy. Concurrent misses of one key share the
singleflight slot: the leader tees, followers re-read local after it
commits or degrade to passthrough after first_byte_ms.
Version reads, partNumber reads, anti-loop marked requests and a respected
local delete marker keep their original 404. Source answers carry
x-rustfs-on-demand-migration: source; local hits are untouched, and the
local hit path gains no await or lock.
* fix(ecstore): persist merged checksum type for full-object multipart
complete_multipart_upload built the object-level checksum record from a
ChecksumType copied before the MULTIPART / INCLUDES_MULTIPART flags were
merged in. ChecksumType::merge takes &mut self, so the merge updated the
local variable while the copy already inside the Checksum struct stayed
behind. The composite branch rebuilt the Checksum from the merged type
and was unaffected; the full-object branch never rebuilt it, so those
flags never reached disk.
rustfs_rio::read_checksums only sets its multipart flag and only emits
the "x-amz-checksum-type" = "FULL_OBJECT" entry inside its MULTIPART
branch, so a full-object multipart object read back as non-multipart with
no type entry, and GetObject and HeadObject answered with no
x-amz-checksum-type header at all where AWS returns FULL_OBJECT.
Hand the full-object branch the merged type instead of rebuilding the
Checksum: the value must stay the running merge produced by add_part,
because hashing the concatenated part digests would yield the COMPOSITE
value, a different number than the one the client sent. The serialization
now lives in multipart_object_checksum_record so both shapes are covered
by unit tests.
Records written by earlier builds carry the bare algorithm type with no
MULTIPART flags and no trailing part block; they keep reading back to the
same checksum value, and the FULL_OBJECT reader arm predates this change
so older peers parse the new record shape correctly too.
Found while root-causing rustfs#6825.
* fix(s3): reject contradicting multipart checksum type as client error
A CompleteMultipartUpload declaring an x-amz-checksum-type that
contradicts the type recorded at CreateMultipartUpload answered 500
InternalError, telling the caller to retry a request that can only ever
fail. The storage layer does refuse the combination, but through a
generic error that maps to InternalError.
Validate the header against the recorded type in the usecase, where the
upload metadata returned by get_multipart_info is already in hand, and
answer InvalidRequest naming both types, matching AWS. The storage-layer
check stays as a backstop for non-HTTP callers.
Uploads created without a checksum algorithm record no type, so there is
nothing to contradict and the header is left alone rather than newly
rejected. Replication is unaffected: replication_put_object_options
already excludes x-amz-checksum-type from the metadata it forwards.
* test(e2e): cover full-object multipart checksum type round-trip
Adds an end-to-end test that a CRC32 FULL_OBJECT multipart upload reports
x-amz-checksum-type: FULL_OBJECT and the unsuffixed full-object value on
both GetObject and HeadObject, and one that a CompleteMultipartUpload
contradicting the recorded type is rejected as InvalidRequest while
leaving the upload intact. Extends the existing CRC64NVME multipart test
with the same checksum-type assertion.
* fix(s3): keep checksum-type validation off the s3s error macro
The s3s footprint ratchet (scripts/check_s3s_footprint.sh) counts
s3_error! invocation lines and is lower-only: new code must route
through the gateway abstractions rather than widen the direct s3s
surface the s3gate migration is shrinking.
Raise the contradiction through ApiError::invalid_request instead. The
response is byte-for-byte identical -- From<ApiError> for S3Error carries
the InvalidRequest code and the message through unchanged -- and the
usecase already returns ApiError elsewhere, so this is the idiomatic
path rather than a way around the counter.
The explanatory comment deliberately says "the s3s error macro" instead
of naming the macro: the ratchet counts raw matches, so spelling it out
in a comment tripped the same check.
* feat(obs): export on-demand migration bucket metrics
Add the on_demand_migration metric subsystem: per-bucket request,
pull, failure, inflight, queue depth, source latency distribution and
breaker state series fed from the ODM runtime snapshot through the
storage boundary, collected alongside bucket replication metrics, and
retired once a bucket's config disappears.
* feat(admin): report the full on-demand migration status snapshot
Extend GET /v3/on-demand-migration/{bucket}/status with provider,
endpoint host, breaker state, runtime counters, last source error,
inflight and queue gauges and the config timestamp. served_by_source_ratio
stays null: no per-bucket GET total exists to divide by. Update the
madmin status type and golden fixture together.
* feat(ecstore): add on-demand migration pull queue and write-back pipeline
Background pull queue per bucket (bounded by pull_queue_capacity, concurrency via the state's pull slot), OdmWriteBack/PullSource traits, single-part and multipart write-back with a pumped body that enforces idle timeout, cancel and content length, retry policy for retryable source errors, inline commit helper, and stats accounting (rustfs/backlog#2153).
* feat(object): implement on-demand migration write-back over internal put
OdmWriteBack impl mapping source heads onto InternalPutContext (content-header allowlist, x-amz-meta copy, tags, dual-prefix odm-* provenance, ETag policy), injected into OnDemandMigrationSys at startup; removes the dead-code gates left by ODM-06a (rustfs/backlog#2153).
feat(object): proxy HEAD misses to the on-demand migration source
Add the ODM HEAD passthrough (rustfs/backlog#2155): after the local lookup
and the replication proxy both miss, resolve the bucket through
OnDemandMigrationSys and answer from the source's HEAD without writing back
or queueing a pull. Versioned reads, requests carrying the source-proxy
anti-loop marker, and a respected latest delete marker never consult the
source; policy.head=local_only, the negative cache and an open breaker
answer 404 locally. Source 404 feeds the negative cache; other source
failures map to 424 SourceUnavailable (class only) or 404 per
policy.source_error, and unsupported source objects always map to 424.
Source answers carry x-rustfs-on-demand-migration: source and omit version,
SSE and replication headers.
The delete-marker probe, request gate, 424 constructor and response marker
live in shared.rs for the GET passthrough to reuse.
* feat(ecstore): add on-demand migration bucket config model
Introduce OnDemandMigrationConfig (deny_unknown_fields, version 1) with typed validation, credential redaction, a secret-free Debug impl, and the OnceLock publish hook the runtime registers into. Exported through the api facade.
* feat(ecstore): persist on-demand migration config in bucket metadata
Store the config as a RustFS extension entry (on-demand-migration.json) with its update time in .metadata.bin, add the typed BucketMetadataSys accessor, and publish the config through the hook on every cache-install path alongside the durability sync.
* refactor(ecstore): extract shared remote S3 client builder
Move the aws_sdk_s3 client construction out of bucket_target_sys into
bucket/remote_s3_client.rs: endpoint assembly, credential provider,
path-style selection, custom CA / skip-TLS transports and the outbound
SSRF gate now build from a neutral RemoteS3EndpointSpec so replication
targets and the upcoming on-demand migration source client share one
policy. Replication builds its client through From<&BucketTarget>; the
gate keeps its relaxed semantics (private allowed, loopback only behind
RUSTFS_REPLICATION_ALLOW_LOOPBACK_TARGET) verbatim. The builder also
gains optional connect/read timeouts and a User-Agent suffix
interceptor, both unset for replication.
Refs rustfs/backlog#2149
* feat(ecstore): add on-demand migration SourceClient
Add bucket/on_demand_migration/source_client.rs on top of the shared
remote S3 builder: HEAD, ranged streaming GET, ListObjectsV2 with
source-prefix mapping, GetObjectTagging and an admin probe. Every request
carries the x-rustfs-/x-minio-source-proxy-request anti-loop markers and
a RustFS-OnDemandMigration/<version> User-Agent suffix; SSE-C source
objects are rejected as unsupported. SourceError classifies SDK failures
(not found, access denied, throttled, timeout, connect, server error)
with retryability and a stable metrics label. Debug output redacts
credentials.
Refs rustfs/backlog#2149
* docs(operations): point outbound policy at shared remote S3 client builder
* chore: integrate ODM-01 and ODM-02 as B1 base (fix facade merge)
* feat(admin): add on-demand migration bucket admin API
Add the management plane for On-Demand Migration (ODM-07,
rustfs/backlog#2154): PUT/GET/DELETE /v3/on-demand-migration/{bucket},
PUT ?dry-run=true, and a GET .../status skeleton.
- PUT authorizes SetBucketOnDemandMigration, checks the bucket, the
RUSTFS_ON_DEMAND_MIGRATION_ENABLED switch and the license, validates the
ODM-01 config against local endpoints and replication targets, probes the
source with SourceClient::probe(), then persists through the incarnation
gate and asks peers to reload. Responses carry the redacted config and a
probe summary; probe failures name only the error class.
- GET answers 404 NoSuchConfiguration when unset; DELETE is idempotent (204).
- New AdminAction variants admin:SetBucketOnDemandMigration and
admin:GetBucketOnDemandMigration, route policy matrix rows, registration
and MinIO alias coverage, and a doc row for the extra handler gates.
- rustfs-madmin gains on_demand_migration wire types and client methods;
golden fixtures under crates/madmin/fixtures/on_demand_migration/ are
asserted byte-for-byte by both the handler and the client tests.
Anonymous sources still map to a 400 naming source.credentials until the
runtime slice adds the credential-less path.
* refactor(admin): route on-demand migration handler errors through the s3 facade
* feat(ecstore): add on-demand migration bucket config model
Introduce OnDemandMigrationConfig (deny_unknown_fields, version 1) with typed validation, credential redaction, a secret-free Debug impl, and the OnceLock publish hook the runtime registers into. Exported through the api facade.
* feat(ecstore): persist on-demand migration config in bucket metadata
Store the config as a RustFS extension entry (on-demand-migration.json) with its update time in .metadata.bin, add the typed BucketMetadataSys accessor, and publish the config through the hook on every cache-install path alongside the durability sync.
* refactor(ecstore): extract shared remote S3 client builder
Move the aws_sdk_s3 client construction out of bucket_target_sys into
bucket/remote_s3_client.rs: endpoint assembly, credential provider,
path-style selection, custom CA / skip-TLS transports and the outbound
SSRF gate now build from a neutral RemoteS3EndpointSpec so replication
targets and the upcoming on-demand migration source client share one
policy. Replication builds its client through From<&BucketTarget>; the
gate keeps its relaxed semantics (private allowed, loopback only behind
RUSTFS_REPLICATION_ALLOW_LOOPBACK_TARGET) verbatim. The builder also
gains optional connect/read timeouts and a User-Agent suffix
interceptor, both unset for replication.
Refs rustfs/backlog#2149
* feat(ecstore): add on-demand migration SourceClient
Add bucket/on_demand_migration/source_client.rs on top of the shared
remote S3 builder: HEAD, ranged streaming GET, ListObjectsV2 with
source-prefix mapping, GetObjectTagging and an admin probe. Every request
carries the x-rustfs-/x-minio-source-proxy-request anti-loop markers and
a RustFS-OnDemandMigration/<version> User-Agent suffix; SSE-C source
objects are rejected as unsupported. SourceError classifies SDK failures
(not found, access denied, throttled, timeout, connect, server error)
with retryability and a stable metrics label. Debug output redacts
credentials.
Refs rustfs/backlog#2149
* docs(operations): point outbound policy at shared remote S3 client builder
* chore: integrate ODM-01 and ODM-02 as B1 base (fix facade merge)
* feat(ecstore): add on-demand migration runtime OnDemandMigrationSys
Per-node runtime for On-Demand Migration (rustfs/backlog#2152): turns each
bucket's persisted config into a live SourceClient guarded by a three-state
circuit breaker, a TTL negative cache, per-key singleflight, a pull
concurrency semaphore and lock-free counters with a serializable snapshot.
- sys.rs: OnceLock singleton; `apply` installs/rebuilds/removes bucket state
(config compared by value, counters preserved across rebuilds, old
cancellation token fired); `publish` is the metadata publish-hook entry
(sync removal, spawned install, generation-ordered so a slow older install
cannot overwrite a newer one); `resolve(bucket, key)` judges module switch,
bucket state, prefix filter, client availability, negative cache, breaker.
- breaker.rs: Closed/Open/HalfOpen with fixed constants (5 failures / 30 s
window / 30 s open / 1 probe); NotFound resets, AccessDenied is neutral.
- negative_cache.rs: moka sync cache keyed by local key, ttl=0 disables.
- stats.rs: requests_total{op,outcome}, pulled_bytes/objects, pull_failures,
inflight/queue gauges, log-bucket latency histogram, last_source_error;
snake_case snapshot pinned by a golden JSON test.
- Anonymous sources surface as a typed `OdmStateError::AnonymousUnsupported`
until the shared client builder gains an anonymous mode.
- rustfs: `RUSTFS_ON_DEMAND_MIGRATION_ENABLED` module switch (default false)
published to module_switches and injected into ecstore before bucket
metadata loads; hook registered at the same point.
* feat(ecstore): add on-demand migration bucket config model
Introduce OnDemandMigrationConfig (deny_unknown_fields, version 1) with typed validation, credential redaction, a secret-free Debug impl, and the OnceLock publish hook the runtime registers into. Exported through the api facade.
* feat(ecstore): persist on-demand migration config in bucket metadata
Store the config as a RustFS extension entry (on-demand-migration.json) with its update time in .metadata.bin, add the typed BucketMetadataSys accessor, and publish the config through the hook on every cache-install path alongside the durability sync.
* test(e2e): rename stall timing variable flagged by typos
* test(storage): heap-pin the RestoreObject usecase future in the generation guard test
* fix(http): drain request bodies after early responses
* fix(http): log early response body drain failures
---------
Co-authored-by: houseme <housemecn@gmail.com>
`build_metrics_summary` emitted a single metric entry for the local
deployment with `online` hardcoded to `true` and `last_online` stamped
with the current time, so `mc admin replicate status` reported "I am
online" rather than whether the remote site was reachable. A peer could
be down for minutes with replication failing while the status page
stayed green, leaving operators with no signal that the link had
dropped.
Emit an entry for every peer instead, deriving `online` from the
`reachable_peers` set the handler already computes by probing each peer,
and take `total_downtime`/`last_online` from the replication heartbeat's
existing `EpHealth` tracking. Node-local replication counters stay on
the local entry so a two-site cluster does not double-count its own
traffic.
The new `BucketTargetSys::endpoint_health` accessor deliberately does not
call `init_hc`: unlike `is_offline` it must not create health entries as
a side effect, or merely rendering the status page would mark an unknown
peer online.
Failure counters (`Errors`) are unchanged and still read zero; that is a
separate defect in the bucket-level statistics path and is not addressed
here.
`local_idp_settings` stamped the site region into the reported OpenID
settings whenever the federated identity service was published, which it
is even with OpenID disabled and no provider configured. The add
preflight compares those settings verbatim, so two sites in different
regions could never be paired: `replicate add` failed with `IDP settings
mismatch` while both sites reported an identical, empty `identity_openid`
config.
Report the empty OpenID settings when no provider is configured, so the
region only qualifies real provider identities, and name the diverging
field in the rejection instead of emitting a bare mismatch. Scalar values
are echoed; nested objects and credential-derived leaves are reported by
presence only.
Fixes#7003
Allow release builds to set RUSTFS_BUILD_VERSION at compile time while keeping the existing tag, short commit, and package-version fallback when the variable is unset or empty.
Co-authored-by: heihutu <heihutu@gmail.com>
overtrue