set configs , but i can't reach 8000 port.
#############################################################################
## Stats Providers
#############################################################################

# Whether statistics are enabled
enableStatistics=true

# The flag to enable recording task execution stats.
enableTaskExecutionStats=true

# Stats Provider Class (if `enableStatistics` are enabled)
# Options:
#   - Prometheus        : org.apache.bookkeeper.stats.prometheus.PrometheusMetricsProvider
#   - Codahale          : org.apache.bookkeeper.stats.codahale.CodahaleMetricsProvider
#   - Twitter Finagle   : org.apache.bookkeeper.stats.twitter.finagle.FinagleStatsProvider
#   - Twitter Ostrich   : org.apache.bookkeeper.stats.twitter.ostrich.OstrichProvider
#   - Twitter Science   : org.apache.bookkeeper.stats.twitter.science.TwitterStatsProvider
# Default value is:
#   org.apache.bookkeeper.stats.prometheus.PrometheusMetricsProvider
#
# For configuring corresponding stats provider, see details at each section below.
#
# statsProviderClass=org.apache.bookkeeper.stats.prometheus.PrometheusMetricsProvider

#############################################################################
## Prometheus Metrics Provider
#############################################################################

# These configs are used when using `PrometheusMetricsProvider`.
statsProviderClass=org.apache.bookkeeper.stats.prometheus.PrometheusMetricsProvider

# Default port for Prometheus metrics exporter
prometheusStatsHttpPort=8000

# latency stats rollover interval, in seconds
prometheusStatsLatencyRolloverSeconds=60
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