7.2. Fuse Online

性能测试显示，活动跟踪逻辑可能会导致 Fuse Online 用来跟踪活动的数据库中的大量死元组。此问题会在需要从数据库读取的任何操作中造成一般的性能下降，特别是从 UI 访问集成列表或刷新集成活动。这个问题的解决方法是通过发出 SQL 语句 VAC UM FULL ANALYSE jsondb 来执行定期维护数据库。

以下是执行此任务的步骤：

# check to see if there are dead tuples (not vacuumed)
$ oc exec -c postgresql $(oc get pod -l 'syndesis.io/component=syndesis-db' --no-headers=true -o=custom-columns=x:.metadata.name) -- bash -c "echo SELECT schemaname, relname, n_live_tup, n_dead_tup, last_autovacuum FROM pg_stat_all_tables WHERE relname = \'jsondb\'|psql -U syndesis"

 schemaname | relname | n_live_tup | n_dead_tup |        last_autovacuum
------------+---------+------------+------------+-------------------------------
 public     | jsondb  |      26893 |     491210 | 2019-07-17 09:26:51.264029+00
(1 row)

# since there are 491210 dead tuples, perform the following

# scale down the server
$ oc scale --replicas=0 dc syndesis-server

# terminate all running connections
$ oc exec -c postgresql $(oc get pod -l 'syndesis.io/component=syndesis-db' --no-headers=true -o=custom-columns=x:.metadata.name) -- bash -c "echo SELECT pg_terminate_backend\(a.pid\) FROM pg_locks l join pg_stat_activity a ON a.pid = l.pid WHERE l.mode = \'ExclusiveLock\' AND a.usename = \'syndesis\'|psql -U syndesis"
FATAL:  terminating connection due to administrator command
server closed the connection unexpectedly
	This probably means the server terminated abnormally
	before or while processing the request.
connection to server was lost
command terminated with exit code 2

# the preceding FATAL error is expected, because the statement also closes the connection psql is using

# execute `VACUUM FULL ANALYSE`
$ oc exec -c postgresql $(oc get pod -l 'syndesis.io/component=syndesis-db' --no-headers=true -o=custom-columns=x:.metadata.name) -- bash -c "echo VACUUM FULL ANALYSE jsondb|psql -U syndesis"
VACUUM

# scale up server
$ oc scale --replicas=1 dc syndesis-server

当使用操作器安装 Fuse Online 时，以下错误会多次发生，但可以忽略它，因为它对安装没有显著影响：

{"level":"error","ts":1558617960.2453232,"logger":"controller","msg":"Error reconciling","action":"*action.startupAction","phase":"Starting","error":"Operation cannot be fulfilled on syndesises.syndesis.io \"app\": the object has been modified; please apply your changes to the latest version and try again","stacktrace":"github.com/syndesisio/syndesis/install/operator/vendor/github.com/go-logr/zapr.(*zapLogger).Error\n\t/go/src/github.com/syndesisio/syndesis/install/operator/vendor/github.com/go-logr/zapr/zapr.go:128\ngithub.com/syndesisio/syndesis/install/operator/pkg/controller/syndesis.(*ReconcileSyndesis).Reconcile\n\t/go/src/github.com/syndesisio/syndesis/install/operator/pkg/controller/syndesis/syndesis_controller.go:120\ngithub.com/syndesisio/syndesis/install/operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem\n\t/go/src/github.com/syndesisio/syndesis/install/operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:215\ngithub.com/syndesisio/syndesis/install/operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func1\n\t/go/src/github.com/syndesisio/syndesis/install/operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:158\ngithub.com/syndesisio/syndesis/install/operator/vendor/k8s.io/apimachinery/pkg/util/wait.JitterUntil.func1\n\t/go/src/github.com/syndesisio/syndesis/install/operator/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:133\ngithub.com/syndesisio/syndesis/install/operator/vendor/k8s.io/apimachinery/pkg/util/wait.JitterUntil\n\t/go/src/github.com/syndesisio/syndesis/install/operator/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:134\ngithub.com/syndesisio/syndesis/install/operator/vendor/k8s.io/apimachinery/pkg/util/wait.Until\n\t/go/src/github.com/syndesisio/syndesis/install/operator/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:88"}