go/vt/vttablet/tabletserver/twopcz.go

// Copyright 2016, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tabletserver

import (
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"

	log "github.com/golang/glog"

	"github.com/youtube/vitess/go/acl"
)

var (
	gridTable = []byte(`<!DOCTYPE html>
	<style type="text/css">
			table.gridtable {
				font-family: verdana,arial,sans-serif;
				font-size: 11px;
				border-width: 1px;
				border-collapse: collapse; table-layout:fixed; overflow: hidden;
			}
			table.gridtable th {
				border-width: 1px;
				padding: 8px;
				border-style: solid;
				background-color: #dedede;
				white-space: nowrap;
			}
			table.gridtable td {
				border-width: 1px;
				padding: 5px;
				border-style: solid;
			}
			table.gridtable th {
				padding-left: 2em;
				padding-right: 2em;
			}
	</style>
	`)
	startTable = []byte(`
	<table class="gridtable">
	`)
	endTable = []byte(`
	</table>
	`)

	failedzHeader = []byte(`
	<h3>Failed Transactions</h3>
	<thead><tr>
		<th>DTID</th>
		<th>Queries</th>
		<th>Time</th>
		<th>Action</th>
	</tr></thead>
	`)
	failedzRow = template.Must(template.New("failedz").Parse(`
	<tr>
		<td>{{.Dtid}}</td>
		<td>{{range .Queries}}{{.}}<br>{{end}}</td>
		<td>{{.Time}}</td>
		<td><form>
			<input type="hidden" name="dtid" value="{{.Dtid}}"></input>
			<input type="submit" name="Action" value="Discard"></input>
		</form></td>
	</tr>
	`))

	preparedzHeader = []byte(`
	<h3>Prepared Transactions</h3>
	<thead><tr>
		<th>DTID</th>
		<th>Queries</th>
		<th>Time</th>
		<th>Action</th>
	</tr></thead>
	`)
	preparedzRow = template.Must(template.New("preparedz").Parse(`
	<tr>
		<td>{{.Dtid}}</td>
		<td>{{range .Queries}}{{.}}<br>{{end}}</td>
		<td>{{.Time}}</td>
		<td><form>
			<input type="hidden" name="dtid" value="{{.Dtid}}"></input>
			<input type="submit" name="Action" value="Rollback"></input>
			<input type="submit" name="Action" value="Commit"></input>
		</form></td>
	</tr>
	`))

	distributedzHeader = []byte(`
	<h3>Distributed Transactions</h3>
	<thead><tr>
		<th>DTID</th>
		<th>State</th>
		<th>Time</th>
		<th>Participants</th>
		<th>Action</th>
	</tr></thead>
	`)
	distributedzRow = template.Must(template.New("distributedz").Parse(`
	<tr>
		<td>{{.Dtid}}</td>
		<td>{{.State}}</td>
		<td>{{.Created}}</td>
		<td>{{range .Participants}}{{.Keyspace}}:{{.Shard}}<br>{{end}}</td>
		<td><form>
			<input type="hidden" name="dtid" value="{{.Dtid}}"></input>
			<input type="submit" name="Action" value="Conclude"></input>
		</form></td>
	</tr>
	`))
)

func twopczHandler(txe *TxExecutor, w http.ResponseWriter, r *http.Request) {
	if err := acl.CheckAccessHTTP(r, acl.DEBUGGING); err != nil {
		acl.SendError(w, err)
		return
	}
	var err error
	dtid := r.FormValue("dtid")
	action := r.FormValue("Action")
	switch action {
	case "Discard", "Rollback":
		err = txe.RollbackPrepared(dtid, 0)
	case "Commit":
		err = txe.CommitPrepared(dtid)
	case "Conclude":
		err = txe.ConcludeTransaction(dtid)
	}
	var msg string
	if action != "" {
		if err != nil {
			msg = err.Error()
			msg = fmt.Sprintf("%s(%s): %v", r.FormValue("Action"), dtid, err)
		} else {
			msg = fmt.Sprintf("%s(%s): completed.", r.FormValue("Action"), dtid)
		}
	}
	distributed, prepared, failed, err := txe.ReadTwopcInflight()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	format := r.FormValue("format")
	if format == "json" {
		w.Header().Set("Content-Type", "application/json")
		js, err := json.Marshal(struct {
			Distributed      []*DistributedTx
			Prepared, Failed []*PreparedTx
		}{
			Distributed: distributed,
			Prepared:    prepared,
			Failed:      failed,
		})
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		w.Write(js)
		return
	}

	w.Write(gridTable)
	w.Write([]byte("<h2>WARNING: Actions on this page can jeopardize data integrity.</h2>\n"))
	if msg != "" {
		w.Write([]byte(fmt.Sprintf("%s\n", msg)))
	}

	w.Write(startTable)
	w.Write(failedzHeader)
	for _, row := range failed {
		if err := failedzRow.Execute(w, row); err != nil {
			log.Errorf("queryz: couldn't execute template: %v", err)
		}
	}
	w.Write(endTable)

	w.Write(startTable)
	w.Write(preparedzHeader)
	for _, row := range prepared {
		if err := preparedzRow.Execute(w, row); err != nil {
			log.Errorf("queryz: couldn't execute template: %v", err)
		}
	}
	w.Write(endTable)

	w.Write(startTable)
	w.Write(distributedzHeader)
	for _, row := range distributed {
		if err := distributedzRow.Execute(w, row); err != nil {
			log.Errorf("queryz: couldn't execute template: %v", err)
		}
	}
	w.Write(endTable)
}