diff --git a/hydro/entry/cli.ts b/hydro/entry/cli.ts
index 839a787ee..0534c8185 100644
--- a/hydro/entry/cli.ts
+++ b/hydro/entry/cli.ts
@@ -1,10 +1,9 @@
-/* eslint-disable no-eval */
 /* eslint-disable no-await-in-loop */
 /* eslint-disable import/no-dynamic-require */
 import { argv } from 'yargs';
 import {
-    lib, service, model, script,
-    builtinLib, builtinScript, builtinModel,
+    lib, service, model,
+    builtinLib, builtinModel,
 } from './common';
 
 const COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;
@@ -45,10 +44,9 @@ async function cli() {
     return console.log(result);
 }
 
-export async function load(call, args) {
-    let pending = args;
+export async function load() {
+    const pending = global.addons;
     const fail = [];
-    const active = [];
     require('../lib/i18n');
     require('../utils');
     require('../error');
@@ -68,21 +66,6 @@ export async function load(call, args) {
     await service(pending, fail);
     for (const i of builtinModel) require(`../model/${i}`);
     await model(pending, fail);
-    for (const i in global.Hydro.service) {
-        if (global.Hydro.service[i].postInit) {
-            try {
-                await global.Hydro.service[i].postInit();
-            } catch (e) {
-                console.error(e);
-            }
-        }
-    }
-    for (const i of builtinScript) require(`../script/${i}`);
-    await script(pending, fail, active);
-    for (const postInit of global.Hydro.postInit) {
-        await postInit();
-    }
-    pending = [];
+    for (const postInit of global.Hydro.postInit) await postInit();
     await cli();
-    return { active, fail };
 }
diff --git a/hydro/entry/master.ts b/hydro/entry/master.ts
index ade691147..eada6452d 100644
--- a/hydro/entry/master.ts
+++ b/hydro/entry/master.ts
@@ -1,8 +1,30 @@
 /* eslint-disable no-await-in-loop */
 /* eslint-disable import/no-dynamic-require */
+import os from 'os';
+import path from 'path';
+import fs from 'fs-extra';
+import { argv } from 'yargs';
 import { builtinModel } from './common';
+import { Entry } from '../loader';
 
-export async function load(call) {
+const tmpdir = path.resolve(os.tmpdir(), 'hydro');
+const lockfile = path.resolve(tmpdir, 'lock.json');
+
+export async function load(call: Entry) {
+    if (fs.existsSync(lockfile) && !argv.ignorelock) {
+        const file = require(lockfile);
+        console.error(`Lockfile exists, pid=${file.pid}`);
+        process.exit(1);
+    }
+    const context = {
+        addons: global.addons,
+        pid: process.pid,
+        ppid: process.ppid,
+    };
+    await fs.writeFile(lockfile, JSON.stringify(context));
+    global.onDestory.push(() => {
+        fs.emptyDirSync(tmpdir);
+    });
     require('../lib/i18n');
     require('../utils');
     require('../error');
diff --git a/hydro/entry/worker.ts b/hydro/entry/worker.ts
index 1691d274a..be89faf8e 100644
--- a/hydro/entry/worker.ts
+++ b/hydro/entry/worker.ts
@@ -5,8 +5,8 @@ import {
     builtinLib, builtinScript, builtinHandler, builtinModel,
 } from './common';
 
-export async function load(call, args) {
-    let pending = args;
+export async function load() {
+    let pending = global.addons;
     const fail = [];
     const active = [];
     require('../lib/i18n');
diff --git a/hydro/handler/problem.ts b/hydro/handler/problem.ts
index 7b36113f6..b895fb09e 100644
--- a/hydro/handler/problem.ts
+++ b/hydro/handler/problem.ts
@@ -206,11 +206,25 @@ class ProblemDetailHandler extends ProblemHandler {
         if (!udoc.hasPerm(PERM.PERM_CREATE_PROBLEM)) {
             throw new PermissionError(PERM.PERM_CREATE_PROBLEM);
         }
-        pid = await problem.add(
-            destDomainId, this.pdoc.pid, this.pdoc.title,
-            this.pdoc.content, this.user._id, this.pdoc.tag,
-            this.pdoc.category, { domainId, pid }, hidden,
-        );
+        if (!this.pdoc.data) {
+            // Copy Without Data
+            pid = await problem.add(
+                destDomainId, this.pdoc.pid, this.pdoc.title,
+                this.pdoc.content, this.user._id, this.pdoc.tag,
+                this.pdoc.category, null, hidden,
+            );
+        } else if (this.pdoc.data instanceof ObjectID) {
+            // With data
+            pid = await problem.add(
+                destDomainId, this.pdoc.pid, this.pdoc.title,
+                this.pdoc.content, this.user._id, this.pdoc.tag,
+                this.pdoc.category, { domainId, pid }, hidden,
+            );
+        } else {
+            // TODO better message
+            // Data should only be copied once.
+            throw new BadRequestError('Cannot copy this problem.');
+        }
         this.response.redirect = this.url('problem_settings', { domainId: destDomainId, pid });
     }
 }
@@ -417,11 +431,24 @@ class ProblemDataDownloadHandler extends ProblemDetailHandler {
         if (this.pdoc.data instanceof ObjectID) {
             this.response.redirect = await file.url(this.pdoc.data, `${this.pdoc.title}.zip`);
         } else if (this.pdoc.data) {
-            // Redirect?
-            this.response.redirect = this.url('problem_data', {
-                domainId: this.pdoc.domainId,
-                pid: this.pdoc.pid,
-            });
+            if (!this.pdoc.data.host) {
+                this.response.redirect = this.url('problem_data', {
+                    domainId: this.pdoc.data.domainId,
+                    pid: this.pdoc.data.pid,
+                });
+            } else {
+                const [scheme, raw] = this.pdoc.data.host.split('//');
+                const args = JSON.parse(Buffer.from(raw, 'base64').toString());
+                if (scheme === 'hydro') {
+                    const [secure, host, port, domainId, id] = args;
+                    this.response.redirect = `http${secure ? 's' : ''}://${host}:${port}/d/${domainId}/p/${id}/data`;
+                } else if (scheme === 'syzoj') {
+                    const [secure, host, port, id] = args;
+                    this.response.redirect = `http${secure ? 's' : ''}://${host}:${port}/problem/${id}/testdata/download`;
+                } else {
+                    throw new ProblemDataNotFoundError(pid);
+                }
+            }
         } else throw new ProblemDataNotFoundError(pid);
     }
 }
diff --git a/hydro/loader.ts b/hydro/loader.ts
index e145170f6..2c884cf0e 100644
--- a/hydro/loader.ts
+++ b/hydro/loader.ts
@@ -54,7 +54,12 @@ async function fork(args: string[] = []) {
     return cluster.fork();
 }
 
-async function entry(config: any) {
+interface EntryConfig {
+    entry: string,
+    newProcess?: boolean,
+}
+
+async function entry(config: EntryConfig) {
     if (config.entry) {
         if (config.newProcess) {
             const sargv = [`--entry=${config.entry}`];
@@ -74,6 +79,8 @@ async function entry(config: any) {
     return null;
 }
 
+export type Entry = typeof entry;
+
 async function stopWorker() {
     cluster.disconnect();
 }
@@ -201,7 +208,7 @@ export async function load() {
         console.log(global.addons);
         if (argv.entry) {
             console.log(`Worker ${process.pid} Starting as ${argv.entry}`);
-            await entry({ entry: argv.entry });
+            await entry({ entry: argv.entry as string });
             console.log(`Worker ${process.pid} Started as ${argv.entry}`);
         } else {
             if (argv.firstWorker) cluster.isFirstWorker = true;
diff --git a/hydro/service/server.ts b/hydro/service/server.ts
index cf6038cfc..8b4205d6f 100644
--- a/hydro/service/server.ts
+++ b/hydro/service/server.ts
@@ -767,6 +767,7 @@ export function Connection(
     sock.installHandlers(server);
 }
 
+// TODO use postInit?
 export async function start() {
     const [disableLog, port] = await system.getMany(['server.log', 'server.port']);
     if (!disableLog) {
diff --git a/locales/en.yaml b/locales/en.yaml
index 00a2db3da..b2f42c414 100644
--- a/locales/en.yaml
+++ b/locales/en.yaml
@@ -54,6 +54,7 @@ perm_problem: Problems
 perm_record: Records
 perm_training: Trainings
 problem_create: Problem Create
+problem_detail: Problem Detail
 problem_edit: Problem Edit
 problem_import: Import Problem
 problem_main: Problem Set
diff --git a/locales/zh_CN.yaml b/locales/zh_CN.yaml
index 9bb158bf4..0df07cb59 100644
--- a/locales/zh_CN.yaml
+++ b/locales/zh_CN.yaml
@@ -523,6 +523,7 @@ Problem Solution List: 题解列表
 Problem Solution: 题解列表
 Problem Tags Visibility: 题目标签可见性
 problem_create: 创建题目
+problem_detail: 题目详情
 problem_edit: 编辑题目
 problem_import: 导入题目
 problem_main: 题库
diff --git a/package.json b/package.json
index 68aadfbde..ee96733a3 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hydrooj",
-  "version": "2.9.12",
+  "version": "2.9.13",
   "main": "dist/loader.js",
   "bin": "bin/hydrooj.js",
   "repository": "https://github.com/hydro-dev/Hydro.git",