diff --git a/src/vs/platform/log/common/log.ts b/src/vs/platform/log/common/log.ts
index 823ec1cd2e06d2098671809eec386100be56e478..f7019d95418e1c906cff8a5eb2f2370058779f14 100644
--- a/src/vs/platform/log/common/log.ts
+++ b/src/vs/platform/log/common/log.ts
@@ -7,8 +7,10 @@
 
 import { IEnvironmentService } from 'vs/platform/environment/common/environment';
 import { createDecorator as createServiceDecorator } from 'vs/platform/instantiation/common/instantiation';
-import { IDisposable } from 'vs/base/common/lifecycle';
+import { IDisposable, Disposable } from 'vs/base/common/lifecycle';
 import { isWindows } from 'vs/base/common/platform';
+import Event, { Emitter } from 'vs/base/common/event';
+import { LogLevelChannelClient } from 'vs/platform/log/common/logIpc';
 
 export const ILogService = createServiceDecorator<ILogService>('logService');
 
@@ -25,6 +27,7 @@ export enum LogLevel {
 export interface ILogService extends IDisposable {
 	_serviceBrand: any;
 
+	onDidChangeLogLevel: Event<LogLevel>;
 	setLevel(level: LogLevel): void;
 	getLevel(): LogLevel;
 	trace(message: string, ...args: any[]): void;
@@ -35,27 +38,37 @@ export interface ILogService extends IDisposable {
 	critical(message: string | Error, ...args: any[]): void;
 }
 
-export class ConsoleLogMainService implements ILogService {
+export abstract class AbstractLogService extends Disposable {
 
-	_serviceBrand: any;
 	private level: LogLevel = LogLevel.Error;
-	private useColors: boolean;
-
-	constructor( @IEnvironmentService environmentService: IEnvironmentService) {
-		this.setLevel(environmentService.logLevel);
-		this.useColors = !isWindows;
-	}
+	private readonly _onDidChangeLogLevel: Emitter<LogLevel> = this._register(new Emitter<LogLevel>());
+	readonly onDidChangeLogLevel: Event<LogLevel> = this._onDidChangeLogLevel.event;
 
 	setLevel(level: LogLevel): void {
-		this.level = level;
+		if (this.level !== level) {
+			this.level = level;
+			this._onDidChangeLogLevel.fire(this.level);
+		}
 	}
 
 	getLevel(): LogLevel {
 		return this.level;
 	}
+}
+
+export class ConsoleLogMainService extends AbstractLogService implements ILogService {
+
+	_serviceBrand: any;
+	private useColors: boolean;
+
+	constructor( @IEnvironmentService environmentService: IEnvironmentService) {
+		super();
+		this.setLevel(environmentService.logLevel);
+		this.useColors = !isWindows;
+	}
 
 	trace(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Trace) {
+		if (this.getLevel() <= LogLevel.Trace) {
 			if (this.useColors) {
 				console.log(`\x1b[90m[main ${new Date().toLocaleTimeString()}]\x1b[0m`, message, ...args);
 			} else {
@@ -65,7 +78,7 @@ export class ConsoleLogMainService implements ILogService {
 	}
 
 	debug(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Debug) {
+		if (this.getLevel() <= LogLevel.Debug) {
 			if (this.useColors) {
 				console.log(`\x1b[90m[main ${new Date().toLocaleTimeString()}]\x1b[0m`, message, ...args);
 			} else {
@@ -75,7 +88,7 @@ export class ConsoleLogMainService implements ILogService {
 	}
 
 	info(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Info) {
+		if (this.getLevel() <= LogLevel.Info) {
 			if (this.useColors) {
 				console.log(`\x1b[90m[main ${new Date().toLocaleTimeString()}]\x1b[0m`, message, ...args);
 			} else {
@@ -85,7 +98,7 @@ export class ConsoleLogMainService implements ILogService {
 	}
 
 	warn(message: string | Error, ...args: any[]): void {
-		if (this.level <= LogLevel.Warning) {
+		if (this.getLevel() <= LogLevel.Warning) {
 			if (this.useColors) {
 				console.warn(`\x1b[93m[main ${new Date().toLocaleTimeString()}]\x1b[0m`, message, ...args);
 			} else {
@@ -95,7 +108,7 @@ export class ConsoleLogMainService implements ILogService {
 	}
 
 	error(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Error) {
+		if (this.getLevel() <= LogLevel.Error) {
 			if (this.useColors) {
 				console.error(`\x1b[91m[main ${new Date().toLocaleTimeString()}]\x1b[0m`, message, ...args);
 			} else {
@@ -105,7 +118,7 @@ export class ConsoleLogMainService implements ILogService {
 	}
 
 	critical(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Critical) {
+		if (this.getLevel() <= LogLevel.Critical) {
 			if (this.useColors) {
 				console.error(`\x1b[90m[main ${new Date().toLocaleTimeString()}]\x1b[0m`, message, ...args);
 			} else {
@@ -119,55 +132,47 @@ export class ConsoleLogMainService implements ILogService {
 	}
 }
 
-export class ConsoleLogService implements ILogService {
+export class ConsoleLogService extends AbstractLogService implements ILogService {
 
 	_serviceBrand: any;
-	private level: LogLevel = LogLevel.Error;
 
 	constructor( @IEnvironmentService environmentService: IEnvironmentService) {
+		super();
 		this.setLevel(environmentService.logLevel);
 	}
 
-	setLevel(level: LogLevel): void {
-		this.level = level;
-	}
-
-	getLevel(): LogLevel {
-		return this.level;
-	}
-
 	trace(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Trace) {
+		if (this.getLevel() <= LogLevel.Trace) {
 			console.log('%cTRACE', 'color: #888', message, ...args);
 		}
 	}
 
 	debug(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Debug) {
+		if (this.getLevel() <= LogLevel.Debug) {
 			console.log('%cDEBUG', 'background: #eee; color: #888', message, ...args);
 		}
 	}
 
 	info(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Info) {
+		if (this.getLevel() <= LogLevel.Info) {
 			console.log('%c INFO', 'color: #33f', message, ...args);
 		}
 	}
 
 	warn(message: string | Error, ...args: any[]): void {
-		if (this.level <= LogLevel.Warning) {
+		if (this.getLevel() <= LogLevel.Warning) {
 			console.log('%c WARN', 'color: #993', message, ...args);
 		}
 	}
 
 	error(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Error) {
+		if (this.getLevel() <= LogLevel.Error) {
 			console.log('%c  ERR', 'color: #f33', message, ...args);
 		}
 	}
 
 	critical(message: string, ...args: any[]): void {
-		if (this.level <= LogLevel.Critical) {
+		if (this.getLevel() <= LogLevel.Critical) {
 			console.log('%cCRITI', 'background: #f33; color: white', message, ...args);
 		}
 	}
@@ -175,22 +180,18 @@ export class ConsoleLogService implements ILogService {
 	dispose(): void { }
 }
 
-export class MultiplexLogService implements ILogService {
+export class MultiplexLogService extends AbstractLogService implements ILogService {
 	_serviceBrand: any;
 
-	constructor(private logServices: ILogService[]) { }
+	constructor(private logServices: ILogService[]) {
+		super();
+	}
 
 	setLevel(level: LogLevel): void {
 		for (const logService of this.logServices) {
 			logService.setLevel(level);
 		}
-	}
-
-	getLevel(): LogLevel {
-		for (const logService of this.logServices) {
-			return logService.getLevel();
-		}
-		return LogLevel.Info;
+		super.setLevel(level);
 	}
 
 	trace(message: string, ...args: any[]): void {
@@ -236,8 +237,50 @@ export class MultiplexLogService implements ILogService {
 	}
 }
 
+export class FollowerLogService extends AbstractLogService implements ILogService {
+	_serviceBrand: any;
+
+	constructor(private client: LogLevelChannelClient, private logService: ILogService) {
+		super();
+		this._register(client.onDidChangeLogLevel(level => logService.setLevel(level)));
+	}
+
+	setLevel(level: LogLevel): void {
+		this.client.setLogLevel(level);
+	}
+
+	trace(message: string, ...args: any[]): void {
+		this.logService.trace(message, ...args);
+	}
+
+	debug(message: string, ...args: any[]): void {
+		this.logService.debug(message, ...args);
+	}
+
+	info(message: string, ...args: any[]): void {
+		this.logService.info(message, ...args);
+	}
+
+	warn(message: string, ...args: any[]): void {
+		this.logService.warn(message, ...args);
+	}
+
+	error(message: string | Error, ...args: any[]): void {
+		this.logService.error(message, ...args);
+	}
+
+	critical(message: string | Error, ...args: any[]): void {
+		this.logService.critical(message, ...args);
+	}
+
+	dispose(): void {
+		this.logService.dispose();
+	}
+}
+
 export class NullLogService implements ILogService {
 	_serviceBrand: any;
+	readonly onDidChangeLogLevel: Event<LogLevel> = new Emitter<LogLevel>().event;
 	setLevel(level: LogLevel): void { }
 	getLevel(): LogLevel { return LogLevel.Info; }
 	trace(message: string, ...args: any[]): void { }