milvus/pkg/metrics/logging_metrics.go
Zhen Ye 27525d57cc
enhance: add glog sink to transfer cgo log into zap (#46721)
issue: #45640

- After async logging, the C log and go log has no order promise,
meanwhile the C log format is not consistent with Go Log; so we close
the output of glog, just forward the log result operation into Go side
which will be handled by the async zap logger.
- Use CGO to filter all cgo logging and promise the order between c log
and go log.
- Also fix the metric name, add new metric to count the logging.
- TODO: after woodpecker use the logger of milvus, we can add bigger
buffer for logging.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
- Core invariant: all C (glog) and Go logs must be routed through the
same zap async pipeline so ordering and formatting are preserved; this
PR ensures every glog emission is captured and forwarded to zap before
any async buffering diverges the outputs.

- Logic removed/simplified: direct glog outputs and hard
stdout/stderr/log_dir settings are disabled (configs/glog.conf and flags
in internal/core/src/config/ConfigKnowhere.cpp) because they are
redundant once a single zap sink handles all logs; logging metrics were
simplified from per-length/volatile gauges to totalized counters
(pkg/metrics/logging_metrics.go & pkg/log/*), removing duplicate
length-tracking and making accounting consistent.

- No data loss or behavior regression (concrete code paths): Google
logging now adds a GoZapSink (internal/core/src/common/logging_c.h,
logging_c.cpp) that calls the exported CGO bridge goZapLogExt
(internal/util/cgo/logging/logging.go). Go side uses
C.GoStringN/C.GoString to capture full message and file, maps glog
severities to zapcore levels, preserves caller info, and writes via the
existing zap async core (same write path used by Go logs). The C++
send() trims glog's trailing newline and forwards exact buffers/lengths,
so message content, file, line, and severity are preserved and
serialized through the same async writer—no log entries are dropped or
reordered relative to Go logs.

- Capability added (where it takes effect): a CGO bridge that forwards
glog into zap—new Go-exported function goZapLogExt
(internal/util/cgo/logging/logging.go), a GoZapSink in C++ that forwards
glog sends (internal/core/src/common/logging_c.h/.cpp), and blank
imports of the cgo initializer across multiple packages (various
internal/* files) to ensure the bridge is registered early so all C logs
are captured.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: chyezh <chyezh@outlook.com>
2026-01-04 14:45:23 +08:00

110 lines
3.8 KiB
Go

// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metrics
import (
"sync"
"github.com/prometheus/client_golang/prometheus"
)
const (
loggingMetricSubsystem = "logging"
)
var (
LoggingMetricsRegisterOnce sync.Once
LoggingPendingWriteTotal = prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "pending_write_total",
Help: "The length of pending writes in the logging buffer",
})
LoggingTruncatedWriteTotal = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "truncated_write_total",
Help: "The number of truncated writes due to exceeding the max bytes per log",
})
LoggingTruncatedWriteBytes = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "truncated_write_bytes",
Help: "The total bytes of truncated writes due to exceeding the max bytes per log",
})
LoggingDroppedWriteTotal = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "dropped_write_total",
Help: "The number of dropped writes due to buffer full or write timeout",
})
LoggingIOFailureTotal = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "io_failure_total",
Help: "The number of IO failures due to underlying write syncer is blocked or write timeout",
})
LoggingWriteTotal = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "write_total",
Help: "The total number of writes",
})
LoggingWriteBytes = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "write_bytes",
Help: "The total bytes of written logs",
})
LoggingCGOWriteTotal = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "cgo_write_total",
Help: "The total number of CGO writes",
})
LoggingCGOWriteBytes = prometheus.NewCounter(prometheus.CounterOpts{
Namespace: milvusNamespace,
Subsystem: loggingMetricSubsystem,
Name: "cgo_write_bytes",
Help: "The total bytes of CGO write logs, the bytes is calculated before encoding, only considers the length of the message, so the actual bytes may be greater than the value",
})
)
// RegisterLoggingMetrics registers logging metrics
func RegisterLoggingMetrics(registry *prometheus.Registry) {
LoggingMetricsRegisterOnce.Do(func() {
registry.MustRegister(LoggingPendingWriteTotal)
registry.MustRegister(LoggingTruncatedWriteTotal)
registry.MustRegister(LoggingTruncatedWriteBytes)
registry.MustRegister(LoggingDroppedWriteTotal)
registry.MustRegister(LoggingIOFailureTotal)
registry.MustRegister(LoggingWriteTotal)
registry.MustRegister(LoggingWriteBytes)
registry.MustRegister(LoggingCGOWriteTotal)
registry.MustRegister(LoggingCGOWriteBytes)
})
}